# Supported Statements ## Data manipulation statements | Statement | Supported | Notes and limitations | | ------------------- | --------- | --------------------------------------------------------------------------------- | | `CALL` | ✅ | | | `CREATE TABLE AS` | ✅ | | | `CREATE TABLE LIKE` | ✅ | | | `DO` | ❌ | | | `DELETE` | ✅ | No support for referring to more than one table in a single `DELETE` statement. | | `HANDLER` | ❌ | | | `IMPORT TABLE` | ❌ | Use `dolt table import` | | `INSERT` | ✅ | Including support for `ON DUPLICATE KEY` clauses. | | `LOAD DATA` | ✅ | | | `LOAD XML` | ❌ | Use `dolt table import` | | `REPLACE` | ✅ | | | `SELECT` | ✅ | Most select statements, including `UNION` and `JOIN`, are supported. | | `SELECT FROM AS OF` | ✅ | Selecting from a table as of any known revision or commit timestamp is supported. | | `SELECT FOR UPDATE` | ❌ | Row-level locks are not supported. | | `SUBQUERIES` | ✅ | Subqueries work, but must be given aliases. Some limitations apply. | | `TABLE` | ✅ | | | `TRUNCATE` | ✅ | | | `UPDATE` | ✅ | No support for referring to more than one table in a single `UPDATE` statement. | | `VALUES` | ✅ | | | `WITH` | ✅ | | | `SELECT INTO` | ✅ | Charset/Collation specification not supported. | ## Data definition statements | Statement | Supported | Notes and limitations | | ----------------------- | --------- | --------------------------------------------------------------------------------------- | | `ADD COLUMN` | ✅ | | | `ADD CHECK` | ✅ | | | `ADD CONSTRAINT` | ✅ | | | `ADD FOREIGN KEY` | ✅ | | | `ADD PARTITION` | ❌ | | | `ALTER COLUMN` | 🟠 | Name and order changes are supported. Some but not all type changes are supported. | | `ALTER DATABASE` | ❌ | | | `ALTER EVENT` | ✅ | Moving events across databases using RENAME TO clause is not supported yet. | | `ALTER INDEX` | ❌ | Indexes can be created and dropped, but not altered. | | `ALTER PRIMARY KEY` | ✅ | | | `ALTER TABLE` | ✅ | Not all `ALTER TABLE` statements are supported. See the rest of this table for details. | | `ALTER TYPE` | 🟠 | Some type changes are supported but not all. | | `ALTER VIEW` | ❌ | Views can be created and dropped, but not altered. | | `CHANGE COLUMN` | ✅ | | | `CREATE DATABASE` | ✅ | Creates a new dolt database rooted relative to the server directory | | `CREATE EVENT` | ✅ | | | `CREATE FUNCTION` | ❌ | | | `CREATE INDEX` | ✅ | | | `CREATE SCHEMA` | ✅ | Creates a new dolt database rooted relative to the server directory | | `CREATE TABLE` | ✅ | | | `CREATE TABLE AS` | ✅ | | | `CREATE TRIGGER` | ✅ | | | `CREATE VIEW` | ✅ | | | `DESCRIBE TABLE` | ✅ | | | `DROP COLUMN` | ✅ | | | `DROP CONSTRAINT` | ✅ | | | `DROP DATABASE` | ✅ | Deletes the dolt data directory. This is unrecoverable. | | `DROP EVENT` | ✅ | | | `DROP FUNCTION` | ❌ | | | `DROP INDEX` | ✅ | | | `DROP SCHEMA` | ✅ | Deletes the dolt data directory. This is unrecoverable. | | `DROP TABLE` | ✅ | | | `DROP PARTITION` | ❌ | | | `DROP PROCEDURE` | ✅ | | | `DROP TRIGGER` | ✅ | | | `DROP VIEW` | ✅ | | | `MODIFY COLUMN` | ✅ | | | `RENAME COLUMN` | ✅ | | | `RENAME CONSTRAINT` | ❌ | | | `RENAME DATABASE` | ❌ | Database names are read-only, but can be configured in the server config. | | `RENAME INDEX` | ❌ | | | `RENAME TABLE` | ✅ | | | `SHOW COLUMNS` | ✅ | | | `SHOW CONSTRAINTS` | ❌ | | | `SHOW CREATE FUNCTION` | ❌ | | | `SHOW CREATE PROCEDURE` | ✅ | | | `SHOW CREATE TABLE` | ✅ | | | `SHOW CREATE VIEW` | ✅ | | | `SHOW DATABASES` | ✅ | | | `SHOW FUNCTION CODE` | ❌ | | | `SHOW FUNCTION STATUS` | ❌ | | | `SHOW GRANTS` | 🟠 | Database privileges, table privileges, and role assumption are not yet implemented. | | `SHOW INDEX` | ❌ | | | `SHOW PRIVILEGES` | ✅ | | | `SHOW PROCEDURE CODE` | ❌ | | | `SHOW PROCEDURE STATUS` | ✅ | | | `SHOW SCHEMAS` | ✅ | | | `SHOW TABLES` | ✅ | `SHOW FULL TABLES` reveals whether a table is a base table or a view. | | `TRUNCATE TABLE` | ✅ | | ## Transactional statements Dolt supports atomic transactions like other SQL databases. It's also possible for clients to connect to different heads, which means they will never see each other's edits until a merge between heads is performed. See [Using Branches](https://docs.dolthub.com/sql-reference/version-control/branches) for more detail. Dolt has two levels of persistence: 1. The SQL transaction layer, where a `COMMIT` statement atomically updates the working set for the connected head 2. The Dolt commit layer, where commits are added to the Dolt commit graph with an author, a parent commit, etc. | Statement | Supported | Notes and limitations | | ----------------------- | --------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `BEGIN` | ✅ | Synonym for `START TRANSACTION` | | `COMMIT` | ✅ | | | `CALL DOLT_COMMIT()` | ✅ | `DOLT_COMMIT()` creates a new Dolt commit using the content of the STAGED HEAD. [See docs on DOLT\_COMMIT() for details.](https://docs.dolthub.com/version-control/dolt-sql-procedures#dolt_commit) | | `LOCK TABLES` | ❌ | `LOCK TABLES` parses correctly but does not prevent access to those tables from other sessions. | | `ROLLBACK` | ✅ | | | `SAVEPOINT` | ✅ | | | `RELEASE SAVEPOINT` | ✅ | | | `ROLLBACK TO SAVEPOINT` | ✅ | | | `@@autocommit` | ✅ | | | `SET TRANSACTION` | ❌ | Different isolation levels are not yet supported. | | `START TRANSACTION` | ✅ | | | `UNLOCK TABLES` | 🟠 | `UNLOCK TABLES` parses correctly, but since `LOCK TABLES` doesn't prevent concurrent access it's essentially a no-op. | ## Prepared statements | Statement | Supported | Notes and limitations | | --------- | --------- | ------------------------------------------------------------- | | `PREPARE` | ✅ | Prepared statements do not work inside of a STORED PROCEDURE. | | `EXECUTE` | ✅ | Execute statments do not work inside of a STORED PROCEDURE. | ## Access management statements More information on how Dolt handles access management may be found in the [access management page](https://docs.dolthub.com/sql-reference/server/access-management). | Statement | Supported | Notes and limitations | | ------------------ | --------- | ----------------------------------------------------------- | | `ALTER USER` | ❌ | | | `CREATE ROLE` | ✅ | | | `CREATE USER` | 🟠 | Only supports basic user creation with an optional password | | `DROP ROLE` | ✅ | | | `DROP USER` | ✅ | | | `GRANT` | 🟠 | Only handles static privileges down to the table level | | `RENAME USER` | ❌ | | | `REVOKE` | 🟠 | Only handles static privileges down to the table level | | `SET DEFAULT ROLE` | ❌ | | | `SET PASSWORD` | ❌ | | | `SET ROLE` | ❌ | | ## Session management statements | Statement | Supported | Notes and limitations | | ------------------- | --------- | --------------------- | | `SET` | ✅ | | | `SET CHARACTER SET` | ✅ | | | `SET NAMES` | ✅ | | | `KILL QUERY` | ✅ | | ## Utility statements | Statement | Supported | Notes and limitations | | --------- | --------- | --------------------- | | `EXPLAIN` | ✅ | | | `USE` | ✅ | | ## Compound statements | Statement | Supported | Notes and limitations | | ----------------------- | --------- | ------------------------------------------------------------------------- | | `BEGIN END` | ✅ | | | `STATEMENT LABELS` | 🟠 | Labels are only supported for `LOOP`. | | `DECLARE` | ✅ | Fully supports declaring variables. | | `DECLARE ... CONDITION` | ✅ | | | `DECLARE ... HANDLER` | 🟠 | Partially supports handling the `NOT FOUND` condition when using cursors. | | `DECLARE ... CURSOR` | ✅ | | | `SET` | ✅ | | | `CASE` | ✅ | | | `IF` | ✅ | | | `ITERATE` | ✅ | | | `LEAVE` | ✅ | | | `LOOP` | ✅ | | | `REPEAT` | ✅ | | | `RETURN` | ❌ | | | `WHILE` | ❌ | | | `CLOSE` | ✅ | | | `FETCH` | ✅ | | | `OPEN` | ✅ | | ## Other administrative statements | Statement | Supported | Notes and limitations | | --------- | --------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `BINLOG` | ✅ | Internal-use statement that replays base64-encoded binary log events. Generated by `mysqlbinlog` or similar utilities. Concurrent `BINLOG` statements can corrupt each other's states; execute through one client at a time only. |