用于 Oracle 检查约束是否存在的 SQL
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SQL for Oracle to check if a constraint exists
提问by Ryan Rodemoyer
In SQL Server I can use the SQL below to check if a constraint exists and if it's a primary key, trigger, etc.
在 SQL Server 中，我可以使用下面的 SQL 来检查约束是否存在以及它是否是主键、触发器等。
SELECT *
FROM dbo.sysobjects
WHERE id = OBJECT_ID(N'[SCHEMA].[TABLENAME]')
AND OBJECTPROPERTY(id, N'IsPrimaryKey') = 1
What would be the Oracle equivalent because my query uses SQL Server specific tables to find the answer.
什么是 Oracle 等效项，因为我的查询使用 SQL Server 特定表来查找答案。
回答by Sathyajith Bhat
SELECT * FROM USER_CONSTRAINTS WHERE CONSTRAINT_NAME = 'CONSTR_NAME';
THE CONSTRAINT_TYPEwill tell you what type of contraint it is
THECONSTRAINT_TYPE会告诉你它是什么类型的约束
- R - Referential key ( foreign key)
- U - Unique key
- P - Primary key
- C - Check constraint
- R - 引用键（外键）
- U - 唯一键
- P - 主键
- C - 检查约束
To find out if an object is a trigger, you can query USER_OBJECTS. OBJECT_TYPEwill tell you if the object's a trigger, view, procedure et al.
要确定对象是否为触发器，您可以查询USER_OBJECTS. OBJECT_TYPE会告诉您对象是否是触发器、视图、过程等。
