在创建存储过程之前,如何检查PERVASIVE数据库中是否存在存储过程?
问题描述:
我想在Pervasive数据库中创建一个存储过程,但前提是该存储过程尚不存在.
I want to create a stored procedure in a Pervasive database, but only if it does not yet exist.
我为SQL Server找到了一些东西
I found something for SQL Server:
IF NOT EXISTS (SELECT *
FROM sys.objects
WHERE type = 'P' AND OBJECT_ID = OBJECT_ID('dbo.MyProc'))
exec('CREATE PROCEDURE [dbo].[MyProc] AS BEGIN SET NOCOUNT ON; END')
GO
我发现此链接上的代码在创建存储过程之前如何检查它是否存在.
I found that code on this link How to check if a stored procedure exists before creating it.
所以我想要与Pervasive真正相似的东西.
So I want something really similar for Pervasive.
答
无法在Pervasive的存储过程之外执行 IF NOT EXISTS
语法.您可以创建一个使用过程名称的过程,并删除该过程名称(如果存在).像这样:
There's no way to execute the IF NOT EXISTS
syntax outside of a Stored Procedure in Pervasive. You could create a procedure taking a procedure name and drop it if it exist. Something like:
CREATE PROCEDURE DropProcIfExists(in :procname char(20))
AS
BEGIN
IF( EXISTS (SELECT xp$Name FROM X$proc WHERE Xp$Name = :procname) ) THEN
Exec('DROP Procedure "' + :procname + '"') ;
END IF;
End#
call DropProcIfExists ('myProc')#
因此您的SQL类似于:
So your SQL would be something like:
call DropProcIfExists('MyNewProc')#
Create Procedure MyNewProc()
AS
BEGIN...