Question

友

我正在创建临时表。脚本可能会运行几次，所以我需要检查临时表是否存在然后删除它。我编写了下面的代码但是在运行脚本两次时出现错误，表已经存在：

数据库中已有一个名为“＃lu_sensor_name_19”的对象。

当tablle不为null时，IF OBJECT_ID('alarm..#lu_sensor_name_19') IS NOT NULL似乎不会返回true。我做错了什么？

IF OBJECT_ID('alarm..#lu_sensor_name_19') IS NOT NULL 
BEGIN 
    DROP TABLE #lu_sensor_name_19 
END

CREATE TABLE #lu_sensor_name_19(
    sensorname_id int NOT NULL,
    sensorname nvarchar(50) NOT NULL,
    paneltype_id smallint NOT NULL,
    panel_version_id int NULL,
    prefix_allowed tinyint NOT NULL,
    base_allowed tinyint NOT NULL,
    suffix_allowed tinyint NOT NULL,
    key_value int NULL,
    sort_index int NULL,
    device_allowed tinyint NOT NULL,
    sensor_name_group_id smallint NOT NULL,
    )

Answer 1

Temp #Tables在tempdb中创建。试试这个：

IF OBJECT_ID('tempdb..#lu_sensor_name_19') IS NOT NULL 
BEGIN 
    DROP TABLE #lu_sensor_name_19 
END

CREATE TABLE #lu_sensor_name_19...

SQL Server 2016增加了在一行中执行删除的功能：

DROP TABLE IF EXISTS #lu_sensor_name_19 

CREATE TABLE #lu_sensor_name_19...

Answer 2

使用此功能。

IF OBJECT_ID('tempdb.dbo.##myTempTable', 'U') IS NOT NULL
BEGIN
    DROP TABLE ##myTempTable;
    --DROP TABLE ##tempdb.dbo.myTempTable;
    /* Above line commented out, because it generates warning:
    "Database name 'tempdb' ignored, referencing object in tempdb.",
    which is a pain in the neck if you are using a temp table to generate SQL code,
    and want to print the code to the screen.*/
END;
GO

CREATE TABLE ##myTempTable(
    FooBar nvarchar(128) not null,
);

并且，在SQL Server 2016中，您可以编写：

DROP TABLE IF EXISTS ##myTempTable

删除临时表（如果存在）

2 个答案: