5.根据主键名或约束名查询所在的表 SELECT conname AS constraint_name, pg_get_constraintdef(con.oid) AS constraint_definition, relname AS table_name FROM pg_constraint con JOIN pg_class cls ON (cls.oid = con.conrelid AND cls.relkind = 'r') -- 只选择关系类型为 "r"(表)的对象 WHERE co...
PostgreSQL: 在PostgreSQL中,你可以通过 ALTER TABLE 命令来删除主键或唯一约束。 sql -- 假设要删除主键约束的表名为 `my_table` ALTER TABLE my_table DROP CONSTRAINT my_primary_key_constraint; -- 假设要删除唯一约束的表名为 `my_table`,约束名为 `unique_constraint_name` ALTER TABLE my_table DROP...
UNIQUE Constraint NOT NULL Constraint DEFAULT Constraint PostgreSQL Data Types Boolean CHAR, VARCHAR, and TEXT NUMERIC DOUBLE PRECISION REAL Integer SERIAL DATE TIMESTAMP Interval TIME UUID JSON HSTORE Array User-defined Data Types Enum XML BYTEA Composite Types Set Operators UNION INTERSECT EXCEPT Cond...
So in the case where we would want to delete a unique_together constraint that had a single field, we'd just look for foo_bar_%_uniq and drop that constraint, here is an SQL statement (in PostgreSQL) that I used in a manual migration (originally from https://stackoverflow.com/a...
CREATE [ TEMPORARY | TEMP ] TABLE table ( column type [ NULL | NOT NULL ] [ UNIQUE ] [ DEFAULT value ] [column_constraint_clause | PRIMARY KEY } [ ...
在腾讯云的产品中,可以使用TencentDB for MySQL或者TencentDB for PostgreSQL来创建和管理数据库。这些产品提供了丰富的功能和工具,可以帮助开发者轻松处理唯一索引或主键冲突的情况。具体产品介绍和链接如下: TencentDB for MySQL:腾讯云提供的高性能、可扩展的MySQL数据库服务。它支持自动备份、容灾、监控等功能,可以有效...
It will show the error of “ERROR: cannot drop index student_pkey because constraint student_pkey on table student requires it”. Examples of PostgreSQL DROP INDEX Below is an example of the drop index command in PostgreSQL. 1. Drop single Index Using Drop Index Command ...
existing_type=postgresql.UUID(), type_=sa.String(length=64), nullable=True, existing_server_default=sa.text('uuid_generate_v4()')) op.create_index(op.f('ix_kernels_sess_id'),'kernels', ['sess_id'], unique=False) op.create_index(op.f('ix_kernels_sess_id_role'),'kernels', ['...
该修复方法适用于所有使用SQL语言的关系型数据库,如MySQL、PostgreSQL、Oracle等。 腾讯云提供了多种云数据库产品,如云数据库MySQL、云数据库PostgreSQL等,可以满足不同业务场景的需求。您可以根据具体需求选择适合的产品。以下是腾讯云云数据库产品的介绍链接: 云数据库MySQL 云数据库PostgreSQL 请注意,本回答中没有提及...
| UNIQUE (column [, column ]...) } constraint_state [ CASCADE ] | RENAME CONSTRAINT old_name TO new_name | { drop_constraint_clause }... } out_of_line_constraint: [ CONSTRAINT constraint_name ] { UNIQUE (column [, column ]...) ...