UPDATE SomeTable SET p_key = CASE WHEN p_key = 'a' THEN 'b' WHEN p_key = 'b' THEN 'a' ELSE p_key END WHERE p_key IN ('a', 'b'); 1. 2. 3. 4. 5. 5、场景五:表之间的数据匹配 WHEN 后的条件中嵌套子查询的 IN 和 EXISTS 谓词 需求:根据 CourseMaster 表和 OpenCourse 表...
ADD CONSTRAINT CHK_PID CHECK (ID>=1 AND PID >=0); -- remove check ALTER TABLE Departments DROP CHECK CHK_PID; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 如果属于数据库逻辑,比如:审计,外键可以使用触发器 CREATE TABLE IF NOT EXISTS `department` ( `id` int NOT NULL AUTO_INCRE...
Whenever you set up a script to create or drop an index, you want a safety check in there. Drop the index if it exists. Create the index if it doesn’t. Or do something else programmatically. Checking if an index exists is a pretty frequent task. But there’s no simple function to ...
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. ...
How to check if a table exists in any of the databases in a server ? For example, I want to see if a table called userAccountsBackup exists in any of the 25 databases in a server. How can I write a query to find this ?
SQL Server Azure SQL Database Azure SQL Managed Instance Checks the integrity of a specified constraint or all constraints on a specified table in the current database. Transact-SQL syntax conventions Syntax syntaxsql DBCCCHECKCONSTRAINTS[ (table_name|table_id|constraint_name|constraint_id) ] [WITH...
When a partitioned table exists on multiple filegroups,DBCC CHECKFILEGROUPchecks the partition rowsets that exist on the specified filegroup and ignores the rowsets in the other filegroups. Informational message 2594 indicates the partitions that weren't checked. Nonclustered indexes not resident on ...
SQL Query to return the data? 1 SELECT 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 ...
public bool RecordExists(string gName, DateTime gDate) { // Set default to false bool returnBool = false; SqlDataSourceEvents.SelectCommand = "SELECT ID, StartTime, EndTime, EventName, UserID, Details FROM EventTable WHERE (DATEPART(day, StartTime) = DATEPART(day, '" + gDate.ToString(...
check_if_table_exists() This assert was triggered when the server tried to load plugins while running in embedded server mode. In embedded server mode, check_if_table_exists() was used to check if mysql.plugin existed so that ER_NO_SUCH_TABLE could be silently ignored. The problem was ...