多个IF EXISTS语句以提升级别

IF EXISTS (SELECT * FROM table_name WHERE condition)
BEGIN
    -- 执行某些操作
END

IF EXISTS (SELECT * FROM information_schema.tables WHERE table_name = 'your_table')
BEGIN
    IF EXISTS (SELECT * FROM information_schema.columns WHERE table_name = 'your_table' AND column_name = 'your_column')
    BEGIN
        -- 执行某些操作
    END
END

CREATE PROCEDURE CheckTableAndColumn
AS
BEGIN
    IF EXISTS (SELECT * FROM information_schema.tables WHERE table_name = 'your_table')
    BEGIN
        IF EXISTS (SELECT * FROM information_schema.columns WHERE table_name = 'your_table' AND column_name = 'your_column')
        BEGIN
            PRINT 'Table and column exist.'
            -- 执行某些操作
        END
        ELSE
        BEGIN
            PRINT 'Column does not exist.'
        END
    END
    ELSE
    BEGIN
        PRINT 'Table does not exist.'
    END
END
GO