after the creation of the second index, can I remove the constraint index? If I can't remove the constraint index is it possible to change the order of an index? If not should I keep the two indexes? Thx for your help. postgresql index postgresql-performance index-tuning unique-constraint...
在PostgreSQL中,你可以使用以下SQL语句来删除主键约束(请注意,删除唯一约束的语法类似,但约束名称可能不同): sql ALTER TABLE my_table DROP CONSTRAINT my_table_pkey; 这里my_table_pkey是主键约束的名称,你需要根据实际情况替换它。 执行SQL语句删除约束: 在数据库管理工具(如pgAdmin、phpMyAdmin等)或命令行...
2) Drop a column that is referenced by a constraint First, attempt to remove the publisher_id column from the books table: ALTER TABLE books DROP COLUMN publisher_id; PostgreSQL issued the following error: ERROR: cannot drop table books column publisher_id because other objects depend on it ...
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...
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 ...
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...
postgresql Share Improve this question Follow asked Apr 17, 2019 at 11:40 Sumuka 1 Add a comment 1 Answer Sorted by: 0 Part 1. Suppose you have a table test CREATE TABLE public.test ( bill integer, fred text, stamp timestamp without time zone ); Add a UNIQUE CONSTRAINT test...
CREATE [ TEMPORARY | TEMP ] TABLE table ( column type [ NULL | NOT NULL ] [ UNIQUE ] [ DEFAULT value ] [column_constraint_clause | PRIMARY KEY } [ ...
An Overview of PostgreSQL Data Types Understanding Numerical Data Types in SQL Comparing TRUNCATE TABLE, DELETE, and DROP TABLE in SQL What Is the DELETE Statement in SQL? See also: How to Remove a Primary Key in SQL How to remove a unique constraint in SQL? How to Delete a Column in ...
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...