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module ActiveRecord
module ConnectionAdapters
module PostgreSQL
module DatabaseStatements
def explain(arel, binds = [])
sql = "EXPLAIN #{to_sql(arel, binds)}"
PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query(sql, "EXPLAIN", binds))
end
def select_value(arel, name = nil, binds = [])
arel, binds = binds_from_relation arel, binds
sql = to_sql(arel, binds)
execute_and_clear(sql, name, binds) do |result|
result.getvalue(0, 0) if result.ntuples > 0 && result.nfields > 0
end
end
def select_values(arel, name = nil, binds = [])
arel, binds = binds_from_relation arel, binds
sql = to_sql(arel, binds)
execute_and_clear(sql, name, binds) do |result|
if result.nfields > 0
result.column_values(0)
else
[]
end
end
end
# Executes a SELECT query and returns an array of rows. Each row is an
# array of field values.
def select_rows(sql, name = nil, binds = [])
execute_and_clear(sql, name, binds) do |result|
result.values
end
end
# The internal PostgreSQL identifier of the money data type.
MONEY_COLUMN_TYPE_OID = 790 #:nodoc:
# The internal PostgreSQL identifier of the BYTEA data type.
BYTEA_COLUMN_TYPE_OID = 17 #:nodoc:
# create a 2D array representing the result set
def result_as_array(res) #:nodoc:
# check if we have any binary column and if they need escaping
ftypes = Array.new(res.nfields) do |i|
[i, res.ftype(i)]
end
rows = res.values
return rows unless ftypes.any? { |_, x|
x == BYTEA_COLUMN_TYPE_OID || x == MONEY_COLUMN_TYPE_OID
}
typehash = ftypes.group_by { |_, type| type }
binaries = typehash[BYTEA_COLUMN_TYPE_OID] || []
monies = typehash[MONEY_COLUMN_TYPE_OID] || []
rows.each do |row|
# unescape string passed BYTEA field (OID == 17)
binaries.each do |index, _|
row[index] = unescape_bytea(row[index])
end
# If this is a money type column and there are any currency symbols,
# then strip them off. Indeed it would be prettier to do this in
# PostgreSQLColumn.string_to_decimal but would break form input
# fields that call value_before_type_cast.
monies.each do |index, _|
data = row[index]
# Because money output is formatted according to the locale, there are two
# cases to consider (note the decimal separators):
# (1) $12,345,678.12
# (2) $12.345.678,12
case data
when /^-?\D+[\d,]+\.\d{2}$/ # (1)
data.gsub!(/[^-\d.]/, "")
when /^-?\D+[\d.]+,\d{2}$/ # (2)
data.gsub!(/[^-\d,]/, "").sub!(/,/, ".")
end
end
end
end
# Queries the database and returns the results in an Array-like object
def query(sql, name = nil) #:nodoc:
log(sql, name) do
result_as_array @connection.async_exec(sql)
end
end
# Executes an SQL statement, returning a PGresult object on success
# or raising a PGError exception otherwise.
# Note: the PGresult object is manually memory managed; if you don't
# need it specifically, you many want consider the exec_query wrapper.
def execute(sql, name = nil)
log(sql, name) do
@connection.async_exec(sql)
end
end
def exec_query(sql, name = "SQL", binds = [], prepare: false)
execute_and_clear(sql, name, binds, prepare: prepare) do |result|
types = {}
fields = result.fields
fields.each_with_index do |fname, i|
ftype = result.ftype i
fmod = result.fmod i
types[fname] = get_oid_type(ftype, fmod, fname)
end
ActiveRecord::Result.new(fields, result.values, types)
end
end
def exec_delete(sql, name = nil, binds = [])
execute_and_clear(sql, name, binds) { |result| result.cmd_tuples }
end
alias :exec_update :exec_delete
def sql_for_insert(sql, pk, id_value, sequence_name, binds) # :nodoc:
if pk.nil?
# Extract the table from the insert sql. Yuck.
table_ref = extract_table_ref_from_insert_sql(sql)
pk = primary_key(table_ref) if table_ref
end
if pk = suppress_composite_primary_key(pk)
sql = "#{sql} RETURNING #{quote_column_name(pk)}"
end
super
end
protected :sql_for_insert
def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
if use_insert_returning? || pk == false
super
else
result = exec_query(sql, name, binds)
unless sequence_name
table_ref = extract_table_ref_from_insert_sql(sql)
if table_ref
pk = primary_key(table_ref) if pk.nil?
pk = suppress_composite_primary_key(pk)
sequence_name = default_sequence_name(table_ref, pk)
end
return result unless sequence_name
end
last_insert_id_result(sequence_name)
end
end
# Begins a transaction.
def begin_db_transaction
execute "BEGIN"
end
def begin_isolated_db_transaction(isolation)
begin_db_transaction
execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
end
# Commits a transaction.
def commit_db_transaction
execute "COMMIT"
end
# Aborts a transaction.
def exec_rollback_db_transaction
execute "ROLLBACK"
end
private
def suppress_composite_primary_key(pk)
pk unless pk.is_a?(Array)
end
end
end
end
end