SQL Query to return the dataSELECT TABLE_NAME FROM DBName.INFORMATION_SCHEMA.Tables WHERE TABLE_NAME='Article' How do I check this in C#?As for how you check that in C#? You just make sure the Row count returned from the query is 1. See this article I have already posted. How do ...
if exists(select * from sysobjects where name=约束名) alter table 表名 drop constraint 约束名; go alter table 表名 add constraint 约束名 check(约束规则),constraint 约束名 check(约束规则); go 示例: -- 添加一个默认约束 use testss; go if exists(select * from sysobjects where name='check1...
it returns theobject ID; otherwise, it returnsNULL. We can use theCOALESCE()function to convert this result into a boolean value. However,this approach returnstrueif any database object with that name exists in the schema, not just a table. ...
if exists(select * from sysobjects where name=约束名) alter table 表名 drop constraint 约束名; go alter table 表名 add constraint 约束名 check(约束规则),constraint 约束名 check(约束规则); go 示例: -- 添加一个默认约束 use testss; go if exists(select * from sysobjects where name='check1...
在MySQL 8.0.16以前,CREATE TABLE允许从语法层面输入下列CHECK约束,但实际没有效果: CHECK (expr) 1. 在MySQL 8.0.16,CREATE TABLE添加了针对所有存储引擎的表和列的CHECK约束的核心特性。CREATE TABLE允许如下针对表或列的约束语法: [CONSTRAINT [symbol]] CHECK (expr) [[NOT] ENFORCED] ...
stuDBgoif exists(select * from Sysobjects where name = 'stuInfo')drop table stuInfogocreate ...
SQL 2005+ EXECUTE master.sys.sp_MSforeachdb 'USE [?]; if exists(select * from INFORMATION_SCHEMA.tables where TABLE_TYPE=''BASE TABLE'' and TABLE_NAME=''DB_BACKUP_LOG_T'') begin print ''exist in '' + db_name() end' SQL 2000 ...
Re: Check if a table exists kamiar kanani January 11, 2007 09:17AM Re: Check if a table exists --> here is a function to use. jeff maass July 19, 2008 05:12PM Sorry, you can't reply to this topic. It has been closed.
$sql = “SELECT * FROM your_table WHERE condition = value”; $result = mysqli_query($conn, $sql); if(mysqli_num_rows($result) > 0) { // 数据库中存在符合条件的记录 // 可以进行相应的操作 } else { // 数据库中不存在符合条件的记录 ...
In MSSQL, checking for column existence is commonly achieved using theINFORMATION SCHEMA – COLUMNSview.Let’s create an.sqlfile to setup the query: $ cat CoulmnTest.sql Use University; ifexists(select*fromINFORMATION_SCHEMA.columnswheretable_name='Course'andcolumn_name='textbook') ...