diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb | 82 |
1 files changed, 37 insertions, 45 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb index b3eb23bbb3..dc4a53034b 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb @@ -1,32 +1,39 @@ -require 'active_support/core_ext/module/deprecation' - module ActiveRecord module ConnectionAdapters # :nodoc: module DatabaseStatements + # Converts an arel AST to SQL + def to_sql(arel) + if arel.respond_to?(:ast) + visitor.accept(arel.ast) + else + arel + end + end + # Returns an array of record hashes with the column names as keys and # column values as values. - def select_all(sql, name = nil, binds = []) - select(sql, name, binds) + def select_all(arel, name = nil, binds = []) + select(to_sql(arel), name, binds) end # Returns a record hash with the column names as keys and column values # as values. - def select_one(sql, name = nil) - result = select_all(sql, name) + def select_one(arel, name = nil) + result = select_all(arel, name) result.first if result end # Returns a single value from a record - def select_value(sql, name = nil) - if result = select_one(sql, name) + def select_value(arel, name = nil) + if result = select_one(arel, name) result.values.first end end # Returns an array of the values of the first column in a select: # select_values("SELECT id FROM companies LIMIT 3") => [1,2,3] - def select_values(sql, name = nil) - result = select_rows(sql, name) + def select_values(arel, name = nil) + result = select_rows(to_sql(arel), name) result.map { |v| v[0] } end @@ -42,7 +49,7 @@ module ActiveRecord undef_method :execute # Executes +sql+ statement in the context of this connection using - # +binds+ as the bind substitutes. +name+ is logged along with + # +binds+ as the bind substitutes. +name+ is logged along with # the executed +sql+ statement. def exec_query(sql, name = 'SQL', binds = []) end @@ -76,20 +83,20 @@ module ActiveRecord # # If the next id was calculated in advance (as in Oracle), it should be # passed in as +id_value+. - def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil, binds = []) - sql, binds = sql_for_insert(sql, pk, id_value, sequence_name, binds) + def insert(arel, name = nil, pk = nil, id_value = nil, sequence_name = nil, binds = []) + sql, binds = sql_for_insert(to_sql(arel), pk, id_value, sequence_name, binds) value = exec_insert(sql, name, binds) id_value || last_inserted_id(value) end # Executes the update statement and returns the number of rows affected. - def update(sql, name = nil, binds = []) - exec_update(sql, name, binds) + def update(arel, name = nil, binds = []) + exec_update(to_sql(arel), name, binds) end # Executes the delete statement and returns the number of rows affected. - def delete(sql, name = nil, binds = []) - exec_delete(sql, name, binds) + def delete(arel, name = nil, binds = []) + exec_delete(to_sql(arel), name, binds) end # Checks whether there is currently no transaction active. This is done @@ -245,38 +252,13 @@ module ActiveRecord # done if the transaction block raises an exception or returns false. def rollback_db_transaction() end - # Appends +LIMIT+ and +OFFSET+ options to an SQL statement, or some SQL - # fragment that has the same semantics as LIMIT and OFFSET. - # - # +options+ must be a Hash which contains a +:limit+ option - # and an +:offset+ option. - # - # This method *modifies* the +sql+ parameter. - # - # This method is deprecated!! Stop using it! - # - # ===== Examples - # add_limit_offset!('SELECT * FROM suppliers', {:limit => 10, :offset => 50}) - # generates - # SELECT * FROM suppliers LIMIT 10 OFFSET 50 - def add_limit_offset!(sql, options) - if limit = options[:limit] - sql << " LIMIT #{sanitize_limit(limit)}" - end - if offset = options[:offset] - sql << " OFFSET #{offset.to_i}" - end - sql - end - deprecate :add_limit_offset! - def default_sequence_name(table, column) nil end # Set the sequence to the max value of the table's column. def reset_sequence!(table, column, sequence = nil) - # Do nothing by default. Implement for PostgreSQL, Oracle, ... + # Do nothing by default. Implement for PostgreSQL, Oracle, ... end # Inserts the given fixture into the table. Overridden in adapters that require @@ -308,10 +290,10 @@ module ActiveRecord # Sanitizes the given LIMIT parameter in order to prevent SQL injection. # # The +limit+ may be anything that can evaluate to a string via #to_s. It - # should look like an integer, or a comma-delimited list of integers, or + # should look like an integer, or a comma-delimited list of integers, or # an Arel SQL literal. # - # Returns Integer and Arel::Nodes::SqlLiteral limits as is. + # Returns Integer and Arel::Nodes::SqlLiteral limits as is. # Returns the sanitized limit parameter, either as an integer, or as a # string which contains a comma-delimited list of integers. def sanitize_limit(limit) @@ -324,6 +306,16 @@ module ActiveRecord end end + # The default strategy for an UPDATE with joins is to use a subquery. This doesn't work + # on mysql (even when aliasing the tables), but mysql allows using JOIN directly in + # an UPDATE statement, so in the mysql adapters we redefine this to do that. + def join_to_update(update, select) #:nodoc: + subselect = select.clone + subselect.projections = [update.key] + + update.where update.key.in(subselect) + end + protected # Returns an array of record hashes with the column names as keys and # column values as values. |