SQL ALTER TABLE Generator
Construct multi-dialect schema migration statements to add, drop, modify columns, or manage constraints.
1 operation
| Action Type | Column Name | New Column Name (Rename) | Data Type & Length | Constraints / Options | Remove |
|---|---|---|---|---|---|
1 statement
ALTER TABLE Syntax Reference
| Operation | MySQL / MariaDB | PostgreSQL | SQL Server |
|---|---|---|---|
| Add Column | ALTER TABLE t ADD COLUMN c INT; |
ALTER TABLE t ADD COLUMN c INT; |
ALTER TABLE t ADD c INT; |
| Drop Column | ALTER TABLE t DROP COLUMN c; |
ALTER TABLE t DROP COLUMN c; |
ALTER TABLE t DROP COLUMN c; |
| Modify Type | ALTER TABLE t MODIFY COLUMN c VARCHAR(100); |
ALTER TABLE t ALTER COLUMN c TYPE VARCHAR(100); |
ALTER TABLE t ALTER COLUMN c VARCHAR(100); |
Frequently Asked Questions
MySQL uses
MODIFY COLUMN, PostgreSQL requires ALTER COLUMN ... TYPE ..., and SQL Server uses ALTER COLUMN without the TYPE keyword. This tool automatically handles dialect-specific syntax translation.