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Revert naive O(1) table_exists? implementation.

It was a bad idea to rescue exceptions here. This can interfere with
transaction rollbacks which seems to be the cause of current CI
failure.

Instead, each adapter should implement its own DB-specific O(1)
implementation, and we fall back on the generic, slower, implementation
otherwise.
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1 parent c7552d9 commit 38703ac8972c7e8f3f3f1ac95aa506cc4ae30ef0 @jonleighton jonleighton committed Dec 13, 2011
@@ -16,17 +16,12 @@ def table_alias_for(table_name)
table_name[0...table_alias_length].gsub(/\./, '_')
end
- # def tables(name = nil) end
-
# Checks to see if the table +table_name+ exists on the database.
#
# === Example
# table_exists?(:developers)
def table_exists?(table_name)
- select_value("SELECT 1 FROM #{quote_table_name(table_name)} where 1=0", 'SCHEMA')
- true
- rescue
- false
+ tables.include?(table_name.to_s)
end
# Returns an array of indexes for the given table.
@@ -152,7 +152,7 @@ def supports_bulk_alter? #:nodoc:
true
end
- # Technically MySQL allows to create indexes with the sort order syntax
+ # Technically MySQL allows to create indexes with the sort order syntax
# but at the moment (5.5) it doesn't yet implement them
def supports_index_sort_order?
true
@@ -363,16 +363,19 @@ def collation
show_variable 'collation_database'
end
- def tables(name = nil, database = nil) #:nodoc:
- sql = ["SHOW TABLES", database].compact.join(' IN ')
+ def tables(name = nil, database = nil, like = nil) #:nodoc:
+ sql = "SHOW TABLES "
+ sql << "IN #{database} " if database
+ sql << "LIKE #{quote(like)}" if like
execute_and_free(sql, 'SCHEMA') do |result|
result.collect { |field| field.first }
end
end
def table_exists?(name)
- return true if super
+ return false unless name
+ return true if tables(nil, nil, name).any?
name = name.to_s
schema, table = name.split('.', 2)
@@ -382,7 +385,7 @@ def table_exists?(name)
schema = nil
end
- tables(nil, schema).include? table
+ tables(nil, schema, table).any?
end
# Returns an array of indexes for the given table.
@@ -329,18 +329,23 @@ def rollback_db_transaction #:nodoc:
# SCHEMA STATEMENTS ========================================
- def tables(name = 'SCHEMA') #:nodoc:
+ def tables(name = 'SCHEMA', table_name = nil) #:nodoc:
sql = <<-SQL
SELECT name
FROM sqlite_master
WHERE type = 'table' AND NOT name = 'sqlite_sequence'
SQL
+ sql << " AND name = #{quote_table_name(table_name)}" if table_name
exec_query(sql, name).map do |row|
row['name']
end
end
+ def table_exists?(name)
+ name && tables('SCHEMA', name).any?
+ end
+
# Returns an array of +SQLiteColumn+ objects for the table specified by +table_name+.
def columns(table_name, name = nil) #:nodoc:
table_structure(table_name).map do |field|
@@ -17,6 +17,7 @@ def test_tables
def test_table_exists?
assert @connection.table_exists?("accounts")
assert !@connection.table_exists?("nonexistingtable")
+ assert !@connection.table_exists?(nil)
end
def test_indexes

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