- B
- C
- D
- E
- F
- I
- N
- R
- S
-
- show_variable,
- strict_mode?,
- supports_advisory_locks?,
- supports_bulk_alter?,
- supports_common_table_expressions?,
- supports_datetime_with_precision?,
- supports_explain?,
- supports_expression_index?,
- supports_foreign_keys?,
- supports_index_sort_order?,
- supports_indexes_in_create?,
- supports_insert_on_duplicate_skip?,
- supports_insert_on_duplicate_update?,
- supports_optimizer_hints?,
- supports_transaction_isolation?,
- supports_views?,
- supports_virtual_columns?
ER_CANNOT_ADD_FOREIGN | = | 1215 |
ER_CANNOT_CREATE_TABLE | = | 1005 |
ER_DATA_TOO_LONG | = | 1406 |
ER_DO_NOT_HAVE_DEFAULT | = | 1364 |
ER_DUP_ENTRY | = | 1062 |
ER_FILSORT_ABORT | = | 1028 |
See dev.mysql.com/doc/refman/5.7/en/error-messages-server.html |
||
ER_FK_INCOMPATIBLE_COLUMNS | = | 3780 |
ER_LOCK_DEADLOCK | = | 1213 |
ER_LOCK_WAIT_TIMEOUT | = | 1205 |
ER_NOT_NULL_VIOLATION | = | 1048 |
ER_NO_REFERENCED_ROW | = | 1216 |
ER_NO_REFERENCED_ROW_2 | = | 1452 |
ER_OUT_OF_RANGE | = | 1264 |
ER_QUERY_INTERRUPTED | = | 1317 |
ER_QUERY_TIMEOUT | = | 3024 |
ER_ROW_IS_REFERENCED | = | 1217 |
ER_ROW_IS_REFERENCED_2 | = | 1451 |
NATIVE_DATABASE_TYPES | = | { primary_key: "bigint auto_increment PRIMARY KEY", string: { name: "varchar", limit: 255 }, text: { name: "text" }, integer: { name: "int", limit: 4 }, float: { name: "float", limit: 24 }, decimal: { name: "decimal" }, datetime: { name: "datetime" }, timestamp: { name: "timestamp" }, time: { name: "time" }, date: { name: "date" }, binary: { name: "blob" }, blob: { name: "blob" }, boolean: { name: "tinyint", limit: 1 }, json: { name: "json" }, } |
By default, the Mysql2Adapter
will consider all columns of type tinyint(1)
as boolean. If you wish to disable this emulation you can add the following line to your application.rb file:
ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = false
Returns the database character set.
Returns the database collation strategy.
Create a new MySQL
database with optional :charset
and :collation
. Charset defaults to utf8mb4.
Example:
create_database 'charset_test', charset: 'latin1', collation: 'latin1_bin'
create_database 'matt_development'
create_database 'matt_development', charset: :big5
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 252 def create_database(name, options = {}) if options[:collation] execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT COLLATE #{quote_table_name(options[:collation])}" elsif options[:charset] execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset])}" elsif row_format_dynamic_by_default? execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET `utf8mb4`" else raise "Configure a supported :charset and ensure innodb_large_prefix is enabled to support indexes on varchar(255) string columns." end end
Drops a table from the database.
:force
-
Set to
:cascade
to drop dependent objects as well. Defaults to false. :if_exists
-
Set to
true
to only drop the table if it exists. Defaults to false. :temporary
-
Set to
true
to drop temporary table. Defaults to false.
Although this command ignores most options
and the block if one is given, it can be helpful to provide these in a migration's change
method so it can be reverted. In that case, options
and the block will be used by create_table.
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 327 def drop_table(table_name, options = {}) execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}" end
Executes the SQL statement in the context of this connection.
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 186 def explain(arel, binds = []) sql = "EXPLAIN #{to_sql(arel, binds)}" start = Concurrent.monotonic_time result = exec_query(sql, "EXPLAIN", binds) elapsed = Concurrent.monotonic_time - start MySQL::ExplainPrettyPrinter.new.pp(result, elapsed) end
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 379 def foreign_keys(table_name) raise ArgumentError unless table_name.present? scope = quoted_scope(table_name) fk_info = exec_query(<<~SQL, "SCHEMA") SELECT fk.referenced_table_name AS 'to_table', fk.referenced_column_name AS 'primary_key', fk.column_name AS 'column', fk.constraint_name AS 'name', rc.update_rule AS 'on_update', rc.delete_rule AS 'on_delete' FROM information_schema.referential_constraints rc JOIN information_schema.key_column_usage fk USING (constraint_schema, constraint_name) WHERE fk.referenced_column_name IS NOT NULL AND fk.table_schema = #{scope[:schema]} AND fk.table_name = #{scope[:name]} AND rc.constraint_schema = #{scope[:schema]} AND rc.table_name = #{scope[:name]} SQL fk_info.map do |row| options = { column: row["column"], name: row["name"], primary_key: row["primary_key"] } options[:on_update] = extract_foreign_key_action(row["on_update"]) options[:on_delete] = extract_foreign_key_action(row["on_delete"]) ForeignKeyDefinition.new(table_name, row["to_table"], options) end end
Drops the database specified on the name
attribute and creates it again using the provided options
.
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 331 def rename_index(table_name, old_name, new_name) if supports_rename_index? validate_index_length!(table_name, new_name) execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}" else super end end
Renames a table.
Example:
rename_table('octopuses', 'octopi')
SHOW VARIABLES LIKE 'name'
See dev.mysql.com/doc/refman/8.0/en/optimizer-hints.html for more details.