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module Sequel
class Dataset
# ---------------------
# :section: 3 - User Methods relating to SQL Creation
# These are methods you can call to see what SQL will be generated by the dataset.
# ---------------------
# Returns a DELETE SQL query string. See +delete+.
#
# dataset.filter{|o| o.price >= 100}.delete_sql
# # => "DELETE FROM items WHERE (price >= 100)"
def delete_sql
return static_sql(opts[:sql]) if opts[:sql]
check_modification_allowed!
clause_sql(:delete)
end
# Returns an EXISTS clause for the dataset as a +LiteralString+.
#
# DB.select(1).where(DB[:items].exists)
# # SELECT 1 WHERE (EXISTS (SELECT * FROM items))
def exists
SQL::PlaceholderLiteralString.new(EXISTS, [self], true)
end
# Returns an INSERT SQL query string. See +insert+.
#
# DB[:items].insert_sql(:a=>1)
# # => "INSERT INTO items (a) VALUES (1)"
def insert_sql(*values)
return static_sql(@opts[:sql]) if @opts[:sql]
check_modification_allowed!
columns = []
case values.size
when 0
return insert_sql({})
when 1
case vals = values.at(0)
when Hash
vals = @opts[:defaults].merge(vals) if @opts[:defaults]
vals = vals.merge(@opts[:overrides]) if @opts[:overrides]
values = []
vals.each do |k,v|
columns << k
values << v
end
when Dataset, Array, LiteralString
values = vals
end
when 2
if (v0 = values.at(0)).is_a?(Array) && ((v1 = values.at(1)).is_a?(Array) || v1.is_a?(Dataset) || v1.is_a?(LiteralString))
columns, values = v0, v1
raise(Error, "Different number of values and columns given to insert_sql") if values.is_a?(Array) and columns.length != values.length
end
end
if values.is_a?(Array) && values.empty? && !insert_supports_empty_values?
columns = [columns().last]
values = [DEFAULT]
end
clone(:columns=>columns, :values=>values)._insert_sql
end
# Returns a literal representation of a value to be used as part
# of an SQL expression.
#
# DB[:items].literal("abc'def\\") #=> "'abc''def\\\\'"
# DB[:items].literal(:items__id) #=> "items.id"
# DB[:items].literal([1, 2, 3]) => "(1, 2, 3)"
# DB[:items].literal(DB[:items]) => "(SELECT * FROM items)"
# DB[:items].literal(:x + 1 > :y) => "((x + 1) > y)"
#
# If an unsupported object is given, an +Error+ is raised.
def literal_append(sql, v)
case v
when Symbol
literal_symbol_append(sql, v)
when String
case v
when LiteralString
sql << v
when SQL::Blob
literal_blob_append(sql, v)
else
literal_string_append(sql, v)
end
when Integer
sql << literal_integer(v)
when Hash
literal_hash_append(sql, v)
when SQL::Expression
literal_expression_append(sql, v)
when Float
sql << literal_float(v)
when BigDecimal
sql << literal_big_decimal(v)
when NilClass
sql << literal_nil
when TrueClass
sql << literal_true
when FalseClass
sql << literal_false
when Array
literal_array_append(sql, v)
when Time
sql << (v.is_a?(SQLTime) ? literal_sqltime(v) : literal_time(v))
when DateTime
sql << literal_datetime(v)
when Date
sql << literal_date(v)
when Dataset
literal_dataset_append(sql, v)
else
literal_other_append(sql, v)
end
end
# Returns an array of insert statements for inserting multiple records.
# This method is used by +multi_insert+ to format insert statements and
# expects a keys array and and an array of value arrays.
#
# This method should be overridden by descendants if the support
# inserting multiple records in a single SQL statement.
def multi_insert_sql(columns, values)
values.map{|r| insert_sql(columns, r)}
end
# Returns a SELECT SQL query string.
#
# dataset.select_sql # => "SELECT * FROM items"
def select_sql
return static_sql(@opts[:sql]) if @opts[:sql]
clause_sql(:select)
end
# Same as +select_sql+, not aliased directly to make subclassing simpler.
def sql
select_sql
end
# Returns a TRUNCATE SQL query string. See +truncate+
#
# DB[:items].truncate_sql # => 'TRUNCATE items'
def truncate_sql
if opts[:sql]
static_sql(opts[:sql])
else
check_truncation_allowed!
raise(InvalidOperation, "Can't truncate filtered datasets") if opts[:where] || opts[:having]
_truncate_sql(source_list(opts[:from]))
end
end
# Formats an UPDATE statement using the given values. See +update+.
#
# DB[:items].update_sql(:price => 100, :category => 'software')
# # => "UPDATE items SET price = 100, category = 'software'
#
# Raises an +Error+ if the dataset is grouped or includes more
# than one table.
def update_sql(values = {})
return static_sql(opts[:sql]) if opts[:sql]
check_modification_allowed!
clone(:values=>values)._update_sql
end
# ---------------------
# :section: 9 - Internal Methods relating to SQL Creation
# These methods, while public, are not designed to be used directly by the end user.
# ---------------------
# Given a type (e.g. select) and an array of clauses,
# return an array of methods to call to build the SQL string.
def self.clause_methods(type, clauses)
clauses.map{|clause| :"#{type}_#{clause}_sql"}.freeze
end
# Map of emulated function names to native function names.
EMULATED_FUNCTION_MAP = {}
WILDCARD = LiteralString.new('*').freeze
ALL = ' ALL'.freeze
AND_SEPARATOR = " AND ".freeze
APOS = "'".freeze
APOS_RE = /'/.freeze
ARRAY_EMPTY = '(NULL)'.freeze
AS = ' AS '.freeze
ASC = ' ASC'.freeze
BOOL_FALSE = "'f'".freeze
BOOL_TRUE = "'t'".freeze
BRACKET_CLOSE = ']'.freeze
BRACKET_OPEN = '['.freeze
CASE_ELSE = " ELSE ".freeze
CASE_END = " END)".freeze
CASE_OPEN = '(CASE'.freeze
CASE_THEN = " THEN ".freeze
CASE_WHEN = " WHEN ".freeze
CAST_OPEN = 'CAST('.freeze
COLUMN_REF_RE1 = Sequel::COLUMN_REF_RE1
COLUMN_REF_RE2 = Sequel::COLUMN_REF_RE2
COLUMN_REF_RE3 = Sequel::COLUMN_REF_RE3
COMMA = ', '.freeze
COMMA_SEPARATOR = COMMA
CONDITION_FALSE = '(1 = 0)'.freeze
CONDITION_TRUE = '(1 = 1)'.freeze
COUNT_FROM_SELF_OPTS = [:distinct, :group, :sql, :limit, :offset, :compounds]
COUNT_OF_ALL_AS_COUNT = SQL::Function.new(:count, WILDCARD).as(:count)
DATASET_ALIAS_BASE_NAME = 't'.freeze
DEFAULT = LiteralString.new('DEFAULT').freeze
DEFAULT_VALUES = " DEFAULT VALUES".freeze
DELETE = 'DELETE'.freeze
DELETE_CLAUSE_METHODS = clause_methods(:delete, %w'delete from where')
DESC = ' DESC'.freeze
DISTINCT = " DISTINCT".freeze
DOT = '.'.freeze
DOUBLE_APOS = "''".freeze
DOUBLE_QUOTE = '""'.freeze
EQUAL = ' = '.freeze
EXTRACT = 'extract('.freeze
EXISTS = ['EXISTS '.freeze].freeze
FOR_UPDATE = ' FOR UPDATE'.freeze
FORMAT_DATE = "'%Y-%m-%d'".freeze
FORMAT_DATE_STANDARD = "DATE '%Y-%m-%d'".freeze
FORMAT_OFFSET = "%+03i%02i".freeze
FORMAT_TIMESTAMP_RE = /%[Nz]/.freeze
FORMAT_TIMESTAMP_USEC = ".%06d".freeze
FORMAT_USEC = '%N'.freeze
FRAME_ALL = "ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING".freeze
FRAME_ROWS = "ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW".freeze
FROM = ' FROM '.freeze
FUNCTION_EMPTY = '()'.freeze
GROUP_BY = " GROUP BY ".freeze
HAVING = " HAVING ".freeze
INSERT = "INSERT".freeze
INSERT_CLAUSE_METHODS = clause_methods(:insert, %w'insert into columns values')
INTO = " INTO ".freeze
IS_LITERALS = {nil=>'NULL'.freeze, true=>'TRUE'.freeze, false=>'FALSE'.freeze}.freeze
IS_OPERATORS = ::Sequel::SQL::ComplexExpression::IS_OPERATORS
LIMIT = " LIMIT ".freeze
N_ARITY_OPERATORS = ::Sequel::SQL::ComplexExpression::N_ARITY_OPERATORS
NOT_SPACE = 'NOT '.freeze
NULL = "NULL".freeze
NULLS_FIRST = " NULLS FIRST".freeze
NULLS_LAST = " NULLS LAST".freeze
OFFSET = " OFFSET ".freeze
ON = ' ON '.freeze
ON_PAREN = " ON (".freeze
ORDER_BY = " ORDER BY ".freeze
ORDER_BY_NS = "ORDER BY ".freeze
OVER = ' OVER '.freeze
PAREN_CLOSE = ')'.freeze
PAREN_OPEN = '('.freeze
PAREN_SPACE_OPEN = ' ('.freeze
PARTITION_BY = "PARTITION BY ".freeze
QUALIFY_KEYS = [:select, :where, :having, :order, :group]
QUESTION_MARK = '?'.freeze
QUESTION_MARK_RE = /\?/.freeze
QUOTE = '"'.freeze
QUOTE_RE = /"/.freeze
RETURNING = " RETURNING ".freeze
SELECT = 'SELECT'.freeze
SELECT_CLAUSE_METHODS = clause_methods(:select, %w'with select distinct columns from join where group having compounds order limit lock')
SET = ' SET '.freeze
SPACE = ' '.freeze
SQL_WITH = "WITH ".freeze
SPACE_WITH = " WITH ".freeze
TILDE = '~'.freeze
TIMESTAMP_FORMAT = "'%Y-%m-%d %H:%M:%S%N%z'".freeze
STANDARD_TIMESTAMP_FORMAT = "TIMESTAMP #{TIMESTAMP_FORMAT}".freeze
TWO_ARITY_OPERATORS = ::Sequel::SQL::ComplexExpression::TWO_ARITY_OPERATORS
REGEXP_OPERATORS = ::Sequel::SQL::ComplexExpression::REGEXP_OPERATORS
UNDERSCORE = '_'.freeze
UPDATE = 'UPDATE'.freeze
UPDATE_CLAUSE_METHODS = clause_methods(:update, %w'update table set where')
USING = ' USING ('.freeze
VALUES = " VALUES ".freeze
V190 = '1.9.0'.freeze
WHERE = " WHERE ".freeze
PUBLIC_APPEND_METHODS = (<<-END).split.map{|x| x.to_sym}
literal
aliased_expression_sql
array_sql
boolean_constant_sql
case_expression_sql
cast_sql
column_all_sql
complex_expression_sql
constant_sql
delayed_evaluation_sql
function_sql
join_clause_sql
join_on_clause_sql
join_using_clause_sql
negative_boolean_constant_sql
ordered_expression_sql
placeholder_literal_string_sql
qualified_identifier_sql
quote_identifier
quote_schema_table
quoted_identifier
subscript_sql
window_sql
window_function_sql
END
PRIVATE_APPEND_METHODS = (<<-END).split.map{|x| x.to_sym}
as_sql
column_list
compound_dataset_sql
expression_list
literal_array
literal_blob
literal_dataset
literal_expression
literal_hash
literal_other
literal_string
literal_symbol
source_list
subselect_sql
table_ref
END
def self.def_append_methods(meths)
meths.each do |meth|
class_eval(<<-END, __FILE__, __LINE__ + 1)
def #{meth}(*args, &block)
s = ''
#{meth}_append(s, *args, &block)
s
end
END
end
end
def_append_methods(PUBLIC_APPEND_METHODS + PRIVATE_APPEND_METHODS)
private *PRIVATE_APPEND_METHODS
# SQL fragment for AliasedExpression
def aliased_expression_sql_append(sql, ae)
literal_append(sql, ae.expression)
as_sql_append(sql, ae.aliaz)
end
# SQL fragment for Array
def array_sql_append(sql, a)
if a.empty?
sql << ARRAY_EMPTY
else
sql << PAREN_OPEN
expression_list_append(sql, a)
sql << PAREN_CLOSE
end
end
# SQL fragment for BooleanConstants
def boolean_constant_sql_append(sql, constant)
if (constant == true || constant == false) && !supports_where_true?
sql << (constant == true ? CONDITION_TRUE : CONDITION_FALSE)
else
literal_append(sql, constant)
end
end
# SQL fragment for CaseExpression
def case_expression_sql_append(sql, ce)
sql << CASE_OPEN
if ce.expression?
sql << SPACE
literal_append(sql, ce.expression)
end
w = CASE_WHEN
t = CASE_THEN
ce.conditions.each do |c,r|
sql << w
literal_append(sql, c)
sql << t
literal_append(sql, r)
end
sql << CASE_ELSE
literal_append(sql, ce.default)
sql << CASE_END
end
# SQL fragment for the SQL CAST expression
def cast_sql_append(sql, expr, type)
sql << CAST_OPEN
literal_append(sql, expr)
sql << AS << db.cast_type_literal(type).to_s
sql << PAREN_CLOSE
end
# SQL fragment for specifying all columns in a given table
def column_all_sql_append(sql, ca)
qualified_identifier_sql_append(sql, ca.table, WILDCARD)
end
# SQL fragment for the complex expression.
def complex_expression_sql_append(sql, op, args)
case op
when *IS_OPERATORS
r = args.at(1)
if r.nil? || supports_is_true?
raise(InvalidOperation, 'Invalid argument used for IS operator') unless v = IS_LITERALS[r]
sql << PAREN_OPEN
literal_append(sql, args.at(0))
sql << SPACE << op.to_s << SPACE
sql << v << PAREN_CLOSE
elsif op == :IS
complex_expression_sql_append(sql, :"=", args)
else
complex_expression_sql_append(sql, :OR, [SQL::BooleanExpression.new(:"!=", *args), SQL::BooleanExpression.new(:IS, args.at(0), nil)])
end
when :IN, :"NOT IN"
cols = args.at(0)
vals = args.at(1)
col_array = true if cols.is_a?(Array)
if vals.is_a?(Array)
val_array = true
empty_val_array = vals == []
end
if empty_val_array
literal_append(sql, empty_array_value(op, cols))
elsif col_array
if !supports_multiple_column_in?
if val_array
expr = SQL::BooleanExpression.new(:OR, *vals.to_a.map{|vs| SQL::BooleanExpression.from_value_pairs(cols.to_a.zip(vs).map{|c, v| [c, v]})})
literal_append(sql, op == :IN ? expr : ~expr)
else
old_vals = vals
vals = vals.naked if vals.is_a?(Sequel::Dataset)
vals = vals.to_a
val_cols = old_vals.columns
complex_expression_sql_append(sql, op, [cols, vals.map!{|x| x.values_at(*val_cols)}])
end
else
# If the columns and values are both arrays, use array_sql instead of
# literal so that if values is an array of two element arrays, it
# will be treated as a value list instead of a condition specifier.
sql << PAREN_OPEN
literal_append(sql, cols)
sql << SPACE << op.to_s << SPACE
if val_array
array_sql_append(sql, vals)
else
literal_append(sql, vals)
end
sql << PAREN_CLOSE
end
else
sql << PAREN_OPEN
literal_append(sql, cols)
sql << SPACE << op.to_s << SPACE
literal_append(sql, vals)
sql << PAREN_CLOSE
end
when *TWO_ARITY_OPERATORS
if REGEXP_OPERATORS.include?(op) && !supports_regexp?
raise InvalidOperation, "Pattern matching via regular expressions is not supported on #{db.database_type}"
end
sql << PAREN_OPEN
literal_append(sql, args.at(0))
sql << SPACE << op.to_s << SPACE
literal_append(sql, args.at(1))
sql << PAREN_CLOSE
when *N_ARITY_OPERATORS
sql << PAREN_OPEN
c = false
op_str = " #{op} "
args.each do |a|
sql << op_str if c
literal_append(sql, a)
c ||= true
end
sql << PAREN_CLOSE
when :NOT
sql << NOT_SPACE
literal_append(sql, args.at(0))
when :NOOP
literal_append(sql, args.at(0))
when :'B~'
sql << TILDE
literal_append(sql, args.at(0))
when :extract
sql << EXTRACT << args.at(0).to_s << FROM
literal_append(sql, args.at(1))
sql << PAREN_CLOSE
else
raise(InvalidOperation, "invalid operator #{op}")
end
end
# SQL fragment for constants
def constant_sql_append(sql, constant)
sql << constant.to_s
end
# SQL fragment for delayed evaluations, evaluating the
# object and literalizing the returned value.
def delayed_evaluation_sql_append(sql, callable)
literal_append(sql, callable.call)
end
# SQL fragment specifying an emulated SQL function call.
# By default, assumes just the function name may need to
# be emulated, adapters should set an EMULATED_FUNCTION_MAP
# hash mapping emulated functions to native functions in
# their dataset class to setup the emulation.
def emulated_function_sql_append(sql, f)
_function_sql_append(sql, native_function_name(f.f), f.args)
end
# SQL fragment specifying an SQL function call without emulation.
def function_sql_append(sql, f)
_function_sql_append(sql, f.f, f.args)
end
# SQL fragment specifying a JOIN clause without ON or USING.
def join_clause_sql_append(sql, jc)
table = jc.table
table_alias = jc.table_alias
table_alias = nil if table == table_alias
sql << SPACE << join_type_sql(jc.join_type) << SPACE
identifier_append(sql, table)
as_sql_append(sql, table_alias) if table_alias
end
# SQL fragment specifying a JOIN clause with ON.
def join_on_clause_sql_append(sql, jc)
join_clause_sql_append(sql, jc)
sql << ON
literal_append(sql, filter_expr(jc.on))
end
# SQL fragment specifying a JOIN clause with USING.
def join_using_clause_sql_append(sql, jc)
join_clause_sql_append(sql, jc)
sql << USING
column_list_append(sql, jc.using)
sql << PAREN_CLOSE
end
# SQL fragment for NegativeBooleanConstants
def negative_boolean_constant_sql_append(sql, constant)
sql << NOT_SPACE
boolean_constant_sql_append(sql, constant)
end
# SQL fragment for the ordered expression, used in the ORDER BY
# clause.
def ordered_expression_sql_append(sql, oe)
literal_append(sql, oe.expression)
sql << (oe.descending ? DESC : ASC)
case oe.nulls
when :first
sql << NULLS_FIRST
when :last
sql << NULLS_LAST
end
end
# SQL fragment for a literal string with placeholders
def placeholder_literal_string_sql_append(sql, pls)
args = pls.args
str = pls.str
sql << PAREN_OPEN if pls.parens
if args.is_a?(Hash)
re = /:(#{args.keys.map{|k| Regexp.escape(k.to_s)}.join('|')})\b/
loop do
previous, q, str = str.partition(re)
sql << previous
literal_append(sql, args[($1||q[1..-1].to_s).to_sym]) unless q.empty?
break if str.empty?
end
elsif str.is_a?(Array)
len = args.length
str.each_with_index do |s, i|
sql << s
literal_append(sql, args[i]) unless i == len
end
else
i = -1
loop do
previous, q, str = str.partition(QUESTION_MARK)
sql << previous
literal_append(sql, args.at(i+=1)) unless q.empty?
break if str.empty?
end
end
sql << PAREN_CLOSE if pls.parens
end
# SQL fragment for the qualifed identifier, specifying
# a table and a column (or schema and table).
# If 3 arguments are given, the 2nd should be the table/qualifier and the third should be
# column/qualified. If 2 arguments are given, the 2nd should be an SQL::QualifiedIdentifier.
def qualified_identifier_sql_append(sql, table, column=(c = table.column; table = table.table; c))
identifier_append(sql, table)
sql << DOT
identifier_append(sql, column)
end
# Adds quoting to identifiers (columns and tables). If identifiers are not
# being quoted, returns name as a string. If identifiers are being quoted
# quote the name with quoted_identifier.
def quote_identifier_append(sql, name)
if name.is_a?(LiteralString)
sql << name
else
name = name.value if name.is_a?(SQL::Identifier)
name = input_identifier(name)
if quote_identifiers?
quoted_identifier_append(sql, name)
else
sql << name
end
end
end
# Separates the schema from the table and returns a string with them
# quoted (if quoting identifiers)
def quote_schema_table_append(sql, table)
schema, table = schema_and_table(table)
if schema
quote_identifier_append(sql, schema)
sql << DOT
end
quote_identifier_append(sql, table)
end
# This method quotes the given name with the SQL standard double quote.
# should be overridden by subclasses to provide quoting not matching the
# SQL standard, such as backtick (used by MySQL and SQLite).
def quoted_identifier_append(sql, name)
sql << QUOTE << name.to_s.gsub(QUOTE_RE, DOUBLE_QUOTE) << QUOTE
end
# Split the schema information from the table, returning two strings,
# one for the schema and one for the table. The returned schema may
# be nil, but the table will always have a string value.
#
# Note that this function does not handle tables with more than one
# level of qualification (e.g. database.schema.table on Microsoft
# SQL Server).
def schema_and_table(table_name, sch=(db.default_schema if db))
sch = sch.to_s if sch
case table_name
when Symbol
s, t, a = split_symbol(table_name)
[s||sch, t]
when SQL::QualifiedIdentifier
[table_name.table.to_s, table_name.column.to_s]
when SQL::Identifier
[sch, table_name.value.to_s]
when String
[sch, table_name.to_s]
else
raise Error, 'table_name should be a Symbol, SQL::QualifiedIdentifier, SQL::Identifier, or String'
end
end
# Splits table_name into an array of strings.
#
# ds.split_qualifiers(:s) # ['s']
# ds.split_qualifiers(:t__s) # ['t', 's']
# ds.split_qualifiers(Sequel.qualify(:d, :t__s)) # ['d', 't', 's']
# ds.split_qualifiers(Sequel.qualify(:h__d, :t__s)) # ['h', 'd', 't', 's']
def split_qualifiers(table_name, *args)
case table_name
when SQL::QualifiedIdentifier
split_qualifiers(table_name.table, nil) + split_qualifiers(table_name.column, nil)
else
sch, table = schema_and_table(table_name, *args)
sch ? [sch, table] : [table]
end
end
# SQL fragment for specifying subscripts (SQL array accesses)
def subscript_sql_append(sql, s)
literal_append(sql, s.f)
sql << BRACKET_OPEN
expression_list_append(sql, s.sub)
sql << BRACKET_CLOSE
end
# The SQL fragment for the given window's options.
def window_sql_append(sql, opts)
raise(Error, 'This dataset does not support window functions') unless supports_window_functions?
sql << PAREN_OPEN
window, part, order, frame = opts.values_at(:window, :partition, :order, :frame)
space = false
space_s = SPACE
if window
literal_append(sql, window)
space = true
end
if part
sql << space_s if space
sql << PARTITION_BY
expression_list_append(sql, Array(part))
space = true
end
if order
sql << space_s if space
sql << ORDER_BY_NS
expression_list_append(sql, Array(order))
space = true
end
case frame
when nil
# nothing
when :all
sql << space_s if space
sql << FRAME_ALL
when :rows
sql << space_s if space
sql << FRAME_ROWS
when String
sql << space_s if space
sql << frame
else
raise Error, "invalid window frame clause, should be :all, :rows, a string, or nil"
end
sql << PAREN_CLOSE
end
# The SQL fragment for the given window function's function and window.
def window_function_sql_append(sql, function, window)
literal_append(sql, function)
sql << OVER
literal_append(sql, window)
end
protected
# Formats in INSERT statement using the stored columns and values.
def _insert_sql
clause_sql(:insert)
end
# Formats an UPDATE statement using the stored values.
def _update_sql
clause_sql(:update)
end
# Return a from_self dataset if an order or limit is specified, so it works as expected
# with UNION, EXCEPT, and INTERSECT clauses.
def compound_from_self
(@opts[:limit] || @opts[:order]) ? from_self : self
end
private
# Backbone of function_sql_append and emulated_function_sql_append.
def _function_sql_append(sql, name, args)
sql << name.to_s
if args.empty?
sql << FUNCTION_EMPTY
else
literal_append(sql, args)
end
end
# Formats the truncate statement. Assumes the table given has already been
# literalized.
def _truncate_sql(table)
"TRUNCATE TABLE #{table}"
end
# Returns an appropriate symbol for the alias represented by s.
def alias_alias_symbol(s)
case s
when Symbol
s
when String
s.to_sym
when SQL::Identifier
s.value.to_s.to_sym
else
raise Error, "Invalid alias for alias_alias_symbol: #{s.inspect}"
end
end
# Returns an appropriate alias symbol for the given object, which can be
# a Symbol, String, SQL::Identifier, SQL::QualifiedIdentifier, or
# SQL::AliasedExpression.
def alias_symbol(sym)
case sym
when Symbol
s, t, a = split_symbol(sym)
a || s ? (a || t).to_sym : sym
when String
sym.to_sym
when SQL::Identifier
sym.value.to_s.to_sym
when SQL::QualifiedIdentifier
alias_symbol(sym.column)
when SQL::AliasedExpression
alias_alias_symbol(sym.aliaz)
else
raise Error, "Invalid alias for alias_symbol: #{sym.inspect}"
end
end
# Clone of this dataset usable in aggregate operations. Does
# a from_self if dataset contains any parameters that would
# affect normal aggregation, or just removes an existing
# order if not.
def aggregate_dataset
options_overlap(COUNT_FROM_SELF_OPTS) ? from_self : unordered
end
# SQL fragment for specifying an alias. expression should already be literalized.
def as_sql_append(sql, aliaz)
sql << AS
quote_identifier_append(sql, aliaz)
end
# Raise an InvalidOperation exception if deletion is not allowed
# for this dataset
def check_modification_allowed!
raise(InvalidOperation, "Grouped datasets cannot be modified") if opts[:group]
raise(InvalidOperation, "Joined datasets cannot be modified") if !supports_modifying_joins? && joined_dataset?
end
# Alias of check_modification_allowed!
def check_truncation_allowed!
check_modification_allowed!
end
# Prepare an SQL statement by calling all clause methods for the given statement type.
def clause_sql(type)
sql = @opts[:append_sql] || sql_string_origin
send("#{type}_clause_methods").each{|x| send(x, sql)}
sql
end
# Converts an array of column names into a comma seperated string of
# column names. If the array is empty, a wildcard (*) is returned.
def column_list_append(sql, columns)
if (columns.nil? || columns.empty?)
sql << WILDCARD
else
expression_list_append(sql, columns)
end
end
# Yield each two pair of arguments to the block, which should
# return a string representing the SQL code for those
# two arguments. If more than 2 arguments are provided, all
# calls to the block # after the first will have a LiteralString
# as the first argument, representing the application of the block to
# the previous arguments.
def complex_expression_arg_pairs(args)
case args.length
when 1
literal(args.at(0))
when 2
yield args.at(0), args.at(1)
else
args.inject{|m, a| LiteralString.new(yield(m, a))}
end
end
# The SQL to use for the dataset used in a UNION/INTERSECT/EXCEPT clause.
def compound_dataset_sql_append(sql, ds)
subselect_sql_append(sql, ds)
end
# The alias to use for datasets, takes a number to make sure the name is unique.
def dataset_alias(number)
:"#{DATASET_ALIAS_BASE_NAME}#{number}"
end
# The strftime format to use when literalizing the time.
def default_timestamp_format
requires_sql_standard_datetimes? ? STANDARD_TIMESTAMP_FORMAT : TIMESTAMP_FORMAT
end
# The order of methods to call to build the DELETE SQL statement
def delete_clause_methods
DELETE_CLAUSE_METHODS
end
def delete_delete_sql(sql)
sql << DELETE
end
# Converts an array of expressions into a comma separated string of
# expressions.
def expression_list_append(sql, columns)
c = false
co = COMMA
columns.each do |col|
sql << co if c
literal_append(sql, col)
c ||= true
end
end
def empty_array_value(op, cols)
if Sequel.empty_array_handle_nulls
c = Array(cols)
SQL::BooleanExpression.from_value_pairs(c.zip(c), :AND, op == :IN)
else
{1 => ((op == :IN) ? 0 : 1)}
end
end
# Format the timestamp based on the default_timestamp_format, with a couple
# of modifiers. First, allow %N to be used for fractions seconds (if the
# database supports them), and override %z to always use a numeric offset
# of hours and minutes.
def format_timestamp(v)
v2 = db.from_application_timestamp(v)
fmt = default_timestamp_format.gsub(FORMAT_TIMESTAMP_RE) do |m|
if m == FORMAT_USEC
format_timestamp_usec(v.is_a?(DateTime) ? v.sec_fraction*(RUBY_VERSION < V190 ? 86400000000 : 1000000) : v.usec) if supports_timestamp_usecs?
else
if supports_timestamp_timezones?
# Would like to just use %z format, but it doesn't appear to work on Windows
# Instead, the offset fragment is constructed manually
minutes = (v2.is_a?(DateTime) ? v2.offset * 1440 : v2.utc_offset/60).to_i
format_timestamp_offset(*minutes.divmod(60))
end
end
end
v2.strftime(fmt)
end
# Return the SQL timestamp fragment to use for the timezone offset.
def format_timestamp_offset(hour, minute)
sprintf(FORMAT_OFFSET, hour, minute)
end
# Return the SQL timestamp fragment to use for the fractional time part.
# Should start with the decimal point. Uses 6 decimal places by default.
def format_timestamp_usec(usec)
sprintf(FORMAT_TIMESTAMP_USEC, usec)
end
# Append the value, but special case regular (non-literal, non-blob) strings
# so that they are considered as identifiers and not SQL strings.
def identifier_append(sql, v)
if v.is_a?(String)
case v
when LiteralString
sql << v
when SQL::Blob
literal_append(sql, v)
else
quote_identifier_append(sql, v)
end
else
literal_append(sql, v)
end
end
alias table_ref_append identifier_append
# Append all identifiers in args interspersed by commas.
def identifier_list_append(sql, args)
c = false
comma = COMMA
args.each do |a|
sql << comma if c
identifier_append(sql, a)
c ||= true
end
end
# Modify the identifier returned from the database based on the
# identifier_output_method.
def input_identifier(v)
(i = identifier_input_method) ? v.to_s.send(i) : v.to_s
end
# SQL fragment specifying the table to insert INTO
def insert_into_sql(sql)
sql << INTO
source_list_append(sql, @opts[:from])
end
# The order of methods to call to build the INSERT SQL statement
def insert_clause_methods
INSERT_CLAUSE_METHODS
end
# SQL fragment specifying the columns to insert into
def insert_columns_sql(sql)
columns = opts[:columns]
if columns && !columns.empty?
sql << PAREN_SPACE_OPEN
identifier_list_append(sql, columns)
sql << PAREN_CLOSE
end
end
def insert_insert_sql(sql)
sql << INSERT
end
# SQL fragment specifying the values to insert.
def insert_values_sql(sql)
case values = opts[:values]
when Array
if values.empty?
sql << DEFAULT_VALUES
else
sql << VALUES
literal_append(sql, values)
end
when Dataset
sql << SPACE
subselect_sql_append(sql, values)
when LiteralString
sql << SPACE << values
else
raise Error, "Unsupported INSERT values type, should be an Array or Dataset: #{values.inspect}"
end
end
# SQL fragment specifying the values to return.
def insert_returning_sql(sql)
if opts.has_key?(:returning)
sql << RETURNING
column_list_append(sql, Array(opts[:returning]))
end
end
alias delete_returning_sql insert_returning_sql
alias update_returning_sql insert_returning_sql
# SQL fragment specifying a JOIN type, converts underscores to
# spaces and upcases.
def join_type_sql(join_type)
"#{join_type.to_s.gsub(UNDERSCORE, SPACE).upcase} JOIN"
end
# Whether this dataset is a joined dataset
def joined_dataset?
(opts[:from].is_a?(Array) && opts[:from].size > 1) || opts[:join]
end
# SQL fragment for Array. Treats as an expression if an array of all two pairs, or as a SQL array otherwise.
def literal_array_append(sql, v)
if Sequel.condition_specifier?(v)
literal_expression_append(sql, SQL::BooleanExpression.from_value_pairs(v))
else
array_sql_append(sql, v)
end
end
# SQL fragment for BigDecimal
def literal_big_decimal(v)
d = v.to_s("F")
v.nan? || v.infinite? ? "'#{d}'" : d
end
# SQL fragment for SQL::Blob
def literal_blob_append(sql, v)
literal_string_append(sql, v)
end
# SQL fragment for Dataset. Does a subselect inside parantheses.
def literal_dataset_append(sql, v)
sql << PAREN_OPEN
subselect_sql_append(sql, v)
sql << PAREN_CLOSE
end
# SQL fragment for Date, using the ISO8601 format.
def literal_date(v)
if requires_sql_standard_datetimes?
v.strftime(FORMAT_DATE_STANDARD)
else
v.strftime(FORMAT_DATE)
end
end
# SQL fragment for DateTime
def literal_datetime(v)
format_timestamp(v)
end
# SQL fragment for SQL::Expression, result depends on the specific type of expression.
def literal_expression_append(sql, v)
v.to_s_append(self, sql)
end
# SQL fragment for false
def literal_false
BOOL_FALSE
end
# SQL fragment for Float
def literal_float(v)
v.to_s
end
# SQL fragment for Hash, treated as an expression
def literal_hash_append(sql, v)
literal_expression_append(sql, SQL::BooleanExpression.from_value_pairs(v))
end
# SQL fragment for Integer
def literal_integer(v)
v.to_s
end
# SQL fragment for nil
def literal_nil
NULL
end
# SQL fragment for a type of object not handled by Dataset#literal.
# Calls +sql_literal+ if object responds to it, otherwise raises an error.
# Classes implementing +sql_literal+ should call a class-specific method on the dataset
# provided and should add that method to Sequel::Dataset, allowing for adapters
# to provide customized literalizations.
# If a database specific type is allowed, this should be overriden in a subclass.
def literal_other_append(sql, v)
if v.respond_to?(:sql_literal_append)
v.sql_literal_append(self, sql)
elsif v.respond_to?(:sql_literal)
sql << v.sql_literal(self)
else
raise Error, "can't express #{v.inspect} as a SQL literal"
end
end
# SQL fragment for Sequel::SQLTime, containing just the time part
def literal_sqltime(v)
v.strftime("'%H:%M:%S#{format_timestamp_usec(v.usec) if supports_timestamp_usecs?}'")
end
# SQL fragment for String. Doubles \ and ' by default.
def literal_string_append(sql, v)
sql << APOS << v.gsub(APOS_RE, DOUBLE_APOS) << APOS
end
# Converts a symbol into a column name. This method supports underscore
# notation in order to express qualified (two underscores) and aliased
# (three underscores) columns:
#
# dataset.literal(:abc) #=> "abc"
# dataset.literal(:abc___a) #=> "abc AS a"
# dataset.literal(:items__abc) #=> "items.abc"
# dataset.literal(:items__abc___a) #=> "items.abc AS a"
def literal_symbol_append(sql, v)
c_table, column, c_alias = split_symbol(v)
if c_table
quote_identifier_append(sql, c_table)
sql << DOT
end
quote_identifier_append(sql, column)
as_sql_append(sql, c_alias) if c_alias
end
# SQL fragment for Time
def literal_time(v)
format_timestamp(v)
end
# SQL fragment for true
def literal_true
BOOL_TRUE
end
# Get the native function name given the emulated function name.
def native_function_name(emulated_function)
self.class.const_get(:EMULATED_FUNCTION_MAP).fetch(emulated_function, emulated_function)
end
# Returns a qualified column name (including a table name) if the column
# name isn't already qualified.
def qualified_column_name(column, table)
if Symbol === column
c_table, column, c_alias = split_symbol(column)
unless c_table
case table
when Symbol
schema, table, t_alias = split_symbol(table)
t_alias ||= Sequel::SQL::QualifiedIdentifier.new(schema, table) if schema
when Sequel::SQL::AliasedExpression
t_alias = table.aliaz
end
c_table = t_alias || table
end
::Sequel::SQL::QualifiedIdentifier.new(c_table, column)
else
column
end
end
# Qualify the given expression e to the given table.
def qualified_expression(e, table)
Qualifier.new(self, table).transform(e)
end
# The order of methods to call to build the SELECT SQL statement
def select_clause_methods
SELECT_CLAUSE_METHODS
end
# Modify the sql to add the columns selected
def select_columns_sql(sql)
sql << SPACE
column_list_append(sql, @opts[:select])
end
# Modify the sql to add the DISTINCT modifier
def select_distinct_sql(sql)
if distinct = @opts[:distinct]
sql << DISTINCT
unless distinct.empty?
sql << ON_PAREN
expression_list_append(sql, distinct)
sql << PAREN_CLOSE
end
end
end
# Modify the sql to add a dataset to the via an EXCEPT, INTERSECT, or UNION clause.
# This uses a subselect for the compound datasets used, because using parantheses doesn't
# work on all databases. I consider this an ugly hack, but can't I think of a better default.
def select_compounds_sql(sql)
return unless c = @opts[:compounds]
c.each do |type, dataset, all|
sql << SPACE << type.to_s.upcase
sql << ALL if all
sql << SPACE
compound_dataset_sql_append(sql, dataset)
end
end
# Modify the sql to add the list of tables to select FROM
def select_from_sql(sql)
if f = @opts[:from]
sql << FROM
source_list_append(sql, f)
end
end
alias delete_from_sql select_from_sql
# Modify the sql to add the expressions to GROUP BY
def select_group_sql(sql)
if group = @opts[:group]
sql << GROUP_BY
if go = @opts[:group_options]
if uses_with_rollup?
expression_list_append(sql, group)
sql << SPACE_WITH << go.to_s.upcase
else
sql << go.to_s.upcase << PAREN_OPEN
expression_list_append(sql, group)
sql << PAREN_CLOSE
end
else
expression_list_append(sql, group)
end
end
end
# Modify the sql to add the filter criteria in the HAVING clause
def select_having_sql(sql)
if having = @opts[:having]
sql << HAVING
literal_append(sql, having)
end
end
# Modify the sql to add the list of tables to JOIN to
def select_join_sql(sql)
if js = @opts[:join]
js.each{|j| literal_append(sql, j)}
end
end
# Modify the sql to limit the number of rows returned and offset
def select_limit_sql(sql)
if l = @opts[:limit]
sql << LIMIT
literal_append(sql, l)
end
if o = @opts[:offset]
sql << OFFSET
literal_append(sql, o)
end
end
# Modify the sql to support the different types of locking modes.
def select_lock_sql(sql)
case l = @opts[:lock]
when :update
sql << FOR_UPDATE
when String
sql << SPACE << l
end
end
# Modify the sql to add the expressions to ORDER BY
def select_order_sql(sql)
if o = @opts[:order]
sql << ORDER_BY
expression_list_append(sql, o)
end
end
alias delete_order_sql select_order_sql
alias update_order_sql select_order_sql
def select_select_sql(sql)
sql << SELECT
end
# Modify the sql to add the filter criteria in the WHERE clause
def select_where_sql(sql)
if w = @opts[:where]
sql << WHERE
literal_append(sql, w)
end
end
alias delete_where_sql select_where_sql
alias update_where_sql select_where_sql
# SQL Fragment specifying the WITH clause
def select_with_sql(sql)
ws = opts[:with]
return if !ws || ws.empty?
sql << select_with_sql_base
c = false
comma = COMMA
ws.each do |w|
sql << comma if c
quote_identifier_append(sql, w[:name])
if args = w[:args]
sql << PAREN_OPEN
identifier_list_append(sql, args)
sql << PAREN_CLOSE
end
sql << AS
literal_dataset_append(sql, w[:dataset])
c ||= true
end
sql << SPACE
end
alias delete_with_sql select_with_sql
alias insert_with_sql select_with_sql
alias update_with_sql select_with_sql
# The base keyword to use for the SQL WITH clause
def select_with_sql_base
SQL_WITH
end
# Converts an array of source names into into a comma separated list.
def source_list_append(sql, sources)
raise(Error, 'No source specified for query') if sources.nil? || sources == []
identifier_list_append(sql, sources)
end
# Delegate to Sequel.split_symbol.
def split_symbol(sym)
Sequel.split_symbol(sym)
end
# The string that is appended to to create the SQL query, the empty
# string by default
def sql_string_origin
''
end
# SQL to use if this dataset uses static SQL. Since static SQL
# can be a PlaceholderLiteralString in addition to a String,
# we literalize nonstrings.
def static_sql(sql)
if append_sql = @opts[:append_sql]
if sql.is_a?(String)
append_sql << sql
else
literal_append(append_sql, sql)
end
else
if sql.is_a?(String)
sql
else
literal(sql)
end
end
end
# SQL fragment for a subselect using the given database's SQL.
def subselect_sql_append(sql, ds)
ds.clone(:append_sql=>sql).sql
end
# The order of methods to call to build the UPDATE SQL statement
def update_clause_methods
UPDATE_CLAUSE_METHODS
end
# SQL fragment specifying the tables from with to delete.
# Includes join table if modifying joins is allowed.
def update_table_sql(sql)
sql << SPACE
source_list_append(sql, @opts[:from])
select_join_sql(sql) if supports_modifying_joins?
end
# The SQL fragment specifying the columns and values to SET.
def update_set_sql(sql)
values = opts[:values]
sql << SET
if values.is_a?(Hash)
values = opts[:defaults].merge(values) if opts[:defaults]
values = values.merge(opts[:overrides]) if opts[:overrides]
c = false
eq = EQUAL
values.each do |k, v|
sql << COMMA if c
if k.is_a?(String) && !k.is_a?(LiteralString)
quote_identifier_append(sql, k)
else
literal_append(sql, k)
end
sql << eq
literal_append(sql, v)
c ||= true
end
else
sql << values
end
end
def update_update_sql(sql)
sql << UPDATE
end
end
end
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