第二步:获取非空约束的名称 在SQL Server 中,非空约束通常会有系统生成的名称。你可以执行以下查询来获取约束的具体名称: -- 查询指定表中所有约束及其类型SELECTCONSTRAINT_NAMEFROMINFORMATION_SCHEMA.TABLE_CONSTRAINTSWHERETABLE_NAME='Employees'ANDCONSTRAINT_TYPE='NOT NULL'; 1. 2. 3. 4. 5. 6. 7. 8....
使用Mermaid语法,以下是列约束的控制流程类图: "包含约束"Employees+int ID+string Name+int AgeConstraints+string ConstraintName+string Type+string TableName 状态图 状态图展示了在删除列约束过程中的各个状态: 确定约束操作成功查看约束选择约束删除约束完成 总结 学习如何在SQL Server中删除列约束是每一位开发者都...
Note that MySQL uses DROP INDEX for index-type constraints such as UNIQUE. Oracle: ALTER TABLE Customer DROP CONSTRAINT Con_First;SQL Server: ALTER TABLE Customer DROP CONSTRAINT Con_First;Next: SQL NULLThis page was last updated on October 12, 2024....
DROP RULE 將會在未來的 SQL Server 版本中移除。 請勿在新的開發工作中使用 DROP RULE ,並計劃修改目前使用這些工作的應用程式。 CHECK請改用CHECK您可以使用 CREATE TABLE 或 ALTER TABLE 關鍵詞建立的條件約束。 如需詳細資訊,請參閱 Unique Constraints and Check Constraints。 Transact-SQL 語法慣例 語法 synta...
The error message “Could not drop object ‘production.brands’ because it is referenced by a FOREIGN KEY constraint. (Microsoft SQL Server, Error: 3726)” is telling us why the table cannot be dropped. In this case we would need to step through dropping the constraints then dropping the ta...
The following example deletes a clustered index with aPRIMARY KEYconstraint by dropping the constraint. TheProductCostHistorytable has noFOREIGN KEYconstraints. If it did, those constraints would have to be removed first. SQL -- Set ONLINE = OFF to execute this example on editions other than En...
In SQL Server, you cannot drop a table if it is referenced by a FOREIGN KEY constraint. You have to either drop the child tables before removing the parent table, or remove foreign key constraints. This article provides a Transact-SQL script to drop fo
Solving Table Drop Error Related to SQL Server Replication's sp_MStran_ddlrepl INSERT INTO new SQL table with SELECT INTO Script to rename constraints and indexes to conform to a SQL Server naming convention Differences between Delete and Truncate Table in SQL Server ...
If it did, those constraints would have to be removed first.SQL Kopiuj -- Set ONLINE = OFF to execute this example on editions other than Enterprise Edition. ALTER TABLE Production.TransactionHistoryArchive DROP CONSTRAINT PK_TransactionHistoryArchive_TransactionID WITH (ONLINE = ON); ...
The following example deletes a clustered index with aPRIMARY KEYconstraint by dropping the constraint. TheProductCostHistorytable has noFOREIGN KEYconstraints. If it did, those constraints would have to be removed first. SQL -- Set ONLINE = OFF to execute this example on editions other than En...