DROP-CREATE

Question

这一年是2009年，SQL Server没有CREATE或ALTER / REPLACE。这就是我所做的。

IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.ROUTINES 
           WHERE ROUTINE_NAME = 'SynchronizeRemoteCatalog' 
             AND ROUTINE_SCHEMA = 'dbo' 
             AND ROUTINE_TYPE = 'PROCEDURE')
 EXEC ('DROP PROCEDURE dbo.SynchronizeRemoteCatalog')

CREATE PROCEDURE dbo.SynchronizeRemoteCatalog
AS BEGIN
    -- body
END

对于触发器，您必须依赖于专有系统视图。

在此期间，这是最受欢迎的惯例吗？

编辑：正如n8wrl建议的那样，official word表明此功能不是高优先级。因此问题。

Answer 1

本文提到了在SQL Server中删除对象时丢失权限的好处。

Tips ‘N’ Tricks – T-SQL – An Elegant way to CREATE or ALTER Stored Procedures in One-Go for Easy Maintenance

所以这是保留权限的方法：

IF OBJECT_ID('spCallSomething') IS NULL
    EXEC('CREATE PROCEDURE spCallSomething AS SET NOCOUNT ON;')
GO

ALTER PROCEDURE spCallSomething ... 
--instead of DROP/CREATE

也适用于函数，只需在上面的代码中将PROCEDURE替换为FUNCTION。

考虑这样做的另一个原因是容忍失败。假设您的DROP成功，但您的CREATE失败 - 您以一个损坏的数据库结束。使用ALTER方法，您将得到该对象的旧版本。

Answer 2

这一年是2009年，SQL Server没有CREATE OR ALTER / REPLACE。

今年是2016年，它现在在SQL Server 2016 RTM和CREATE OR ALTER（2016 SP1中引入）中有DIE（Drop If Exists）。

首先考虑Drop If Exists需要使用此方法重新应用权限的警告仍然适用。语法示例是

DROP PROCEDURE IF EXISTS dbo.SynchronizeRemoteCatalog

GO

CREATE PROCEDURE dbo.SynchronizeRemoteCatalog
AS
  BEGIN
      BODY:
  END 

GO

/*TODO: Reapply permissions*/

CREATE OR ALTER保留权限。语法示例是

 CREATE OR ALTER PROCEDURE dbo.SynchronizeRemoteCatalog
 AS
 BEGIN
   BODY:
 END

corresponding MSSQL Tiger Team blog post解释了

CREATE OR ALTER可用于可编程对象，例如：


存储过程（包括本地编译）

功能（Transact-SQL，包括本机编译）

TRIGGERS

VIEWS


但不能用于：


需要存储的对象（表，索引和索引视图）

CLR用户定义函数

已弃用的可编程对象（RULE和DEFAULT）

非可编程对象（例如CREATE ASSEMBLY，CREATE TABLE或CREATE - SCHEMA）。在这些对象上，CREATE和的语法   ALTER与语法和可用性方面有很大不同。

Answer 3

每次开发人员写IF EXISTS(...) DROP时，海豹幼崽都会被殴打。您应该确切知道数据库中的内容，并且升级脚本应根据应用程序架构的当前版本执行CREATe或ALTER：Version Control and your Database。

Answer 4

我们遇到了需要更新远程站点的情况，但我们没有DROP权限。到目前为止，我们一直在使用SSMS 2008 R2中内置的“DROP和CREATE”脚本，但现在我们需要更改。我们创建了三个模板，当我们需要更新存储过程或函数时，我们将其放在相应的ALTER脚本之上：

—- Stored Procedure
IF OBJECT_ID('[dbo].[<Name_Of_Routine, , >]') IS NULL
EXEC('CREATE PROCEDURE [dbo].[<Name_Of_Routine, , >] AS SET NOCOUNT ON;')
EXEC('GRANT EXECUTE ON [<Name_Of_Routine, , >] TO Public AS dbo;')
GO

—- Scalar Function
IF OBJECT_ID('[dbo].[<Name_Of_Routine, , >]') IS NULL
EXEC('CREATE FUNCTION [dbo].[<Name_Of_Routine, , >] (@i INT) RETURNS INT AS BEGIN RETURN 0 END;')
EXEC('GRANT EXECUTE ON [<Name_Of_Routine, , >] TO Public AS dbo;')
GO

—- Table-based Function
IF OBJECT_ID('[dbo].[<Name_Of_Routine, , >]') IS NULL
EXEC('CREATE FUNCTION [dbo].[<Name_Of_Routine, , >] (@i INT) RETURNS @O TABLE(i INT) AS BEGIN INSERT INTO @O SELECT 0 RETURN END;')
GO

在每次CREATE之后，任何特殊权限都会被编写脚本（无法为表函数分配权限）。之后，ALTER不会更改它，如果他们添加或修改权限，它们将保留。这样做，复制函数或存储过程的名称是一项简单的任务，并使用模板参数替换来自动完成这些scriptlet。

现在，我希望微软的优秀人员能够将其添加到他们的“Script ___ as”列表中，或者让我们能够创建自己的脚本，以便这个脚本来自“烘焙”

您可能希望在SQL Server反馈条目后面增加一些权重： https://connect.microsoft.com/SQLServer/feedback/details/344991/create-or-alter-statement。它似乎是少数几个仍然可以公开访问的产品之一，他们声称他们“已经开始对此进行可行性审查，以决定我们是否可以在不久的将来发货。”声音越多，就越有可能发生这种情况！

（更新：现在还使用以下触发器和视图代码）

-- Triggers
IF OBJECT_ID('[dbo].[<Name_Of_Trigger, , >]') IS NULL -- Check if Trigger Exists
    EXEC('CREATE TRIGGER [dbo].[<Name_Of_Trigger, , >] ON [<Name_Of_Table, , >] AFTER UPDATE AS SET NOCOUNT ON;') -- Create dummy/empty SP
GO

-- Views
IF OBJECT_ID('[dbo].[<Name_Of_View, , >]') IS NULL -- Check if View Exists
    EXEC('CREATE VIEW [dbo].[<Name_Of_View, , >] AS SELECT 1;') -- Create dummy/empty View
GO

Answer 5

我在DROP之前使用OBJECT_ID(...) IS NOT NULL。

对象标识符必须是唯一的，因此无需使用系统表即可运行：

CREATE TRIGGER dbo.ExistingTable ON dbo.AnotherTable FOR UPDATE
AS 
SET NOCOUNT ON
GO

给出

Msg 2714, Level 16, State 2, Procedure MetaClass, Line 3
There is already an object named ExistingTable ' in the database.

我通常使用ALTER，因为我们使用源代码控制等等。

Answer 6

这基本上是做到这一点的方式，是的。我只是想知道你是否有特别的理由使用“EXEC”方法：

IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME = 'SynchronizeRemoteCatalog' AND ROUTINE_SCHEMA = 'dbo' AND ROUTINE_TYPE = 'PROCEDURE')
    EXEC ('DROP PROCEDURE dbo.SynchronizeRemoteCatalog')

为什么不呢：

IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME = 'SynchronizeRemoteCatalog' AND ROUTINE_SCHEMA = 'dbo' AND ROUTINE_TYPE = 'PROCEDURE')
    DROP PROCEDURE dbo.SynchronizeRemoteCatalog

???

对于触发器，有sys.triggers。那些是“sys”模式中的系统目录视图 - 不是严格或直接表，实际上。

马克

Answer 7

我总是alter我的对象，因为drop是非常糟糕的做法，如果对象无法创建（24/7 db！），以及什么，可能会使数据库处于错误状态其他海报提到了关于核权的问题。

像Sublime，Atom和VS Code这样的编辑器将允许您将代码片段作为模板，以便快速生成您的骨架脚本。 SQL 2016现在终于支持DROP IF EXISTS构造，但它仍然从错误的方向接近 - 在遥远的过去，所有内容都是drop/create而不是一次create alter从那时起。此外，我试图让我的标题尽可能短，因此我不会像create proc dbo.myproc as存根那样获得create之前的任何标记。

查看：

if objectproperty(object_id('dbo.myview'), 'IsView') is null begin
    exec('create view dbo.myview as select 1 c')
end
go
alter view dbo.myview as
    -- select *
    -- from table
go

PROCS：

if objectproperty(object_id('dbo.myproc'), 'IsProcedure') is null begin
    exec('create proc dbo.myproc as')
end
go
alter procedure dbo.myproc as
    set nocount on
    -- Add the stored proc contents here...
go

UDF（标量）：

if objectproperty(object_id('dbo.myudf'), 'IsScalarFunction') is null begin
    exec('create function dbo.myudf returns int as begin return null end')
end
go
alter function dbo.myudf(@s varchar(100)) returns int as
begin
    -- return len(@s)
end
go

UDF（表格）：

if objectproperty(object_id('dbo.myudf'), 'IsTableFunction') is null begin
    exec('create function dbo.myudf returns @t table(x int) as begin return end')
end
go
alter function dbo.myudf(@s varchar(100))
    returns @result table (
        -- Columns returned by the function
        id int identity(1, 1) primary key not null
        ,result varchar(100) null
    )
begin
    return
end
go

Answer 8

看起来有点休息：link text

我的典型脚本：

IF EXISTS (SELECT name FROM sysobjects WHERE name = 'ig_InsertDealer' AND type = 'P')
    DROP PROC dbo.ig_InsertDealer
GO 
CREATE PROCEDURE dbo.ig_InsertDealer
...
GO
GRANT EXECUTE ON dbo.ig_InsertDealer TO ...
GO

Answer 9

我将根据上下文使用：我的初始构建或主要重构脚本将使用check / drop / create，纯维护脚本使用alter。

Answer 10

我更喜欢CREATE-ALTER方法（不是语法）超过DROP-CREATE，原因有两个：

权限（DROP-CREATE必须重新创建）
object_id（改变对象不会改变它）

示例DROP-CREATE：

--Initial creation:
CREATE PROCEDURE dbo.my_proc
AS
SELECT *
FROM dbo.a
WHERE i < 10;
GO

SELECT OBJECT_ID('dbo.my_proc');
GO


-- Recreating
DROP PROCEDURE IF EXISTS dbo.my_proc;
GO

CREATE PROCEDURE dbo.my_proc
AS
-- some meaningless comment
SELECT *
FROM dbo.a
WHERE i < 10;
GO

SELECT OBJECT_ID('dbo.my_proc');
GO

<强> DB Fiddle

我们可以看到object_id已发生变化。

示例2：CREATE-ALTER

-- Initial creation
CREATE PROCEDURE dbo.my_proc2
AS
SELECT *
FROM dbo.a
WHERE i < 10;
GO

SELECT OBJECT_ID('dbo.my_proc2');
GO

-- Altering
CREATE OR ALTER PROCEDURE dbo.my_proc2
AS
-- some meaningless comment
SELECT *
FROM dbo.a
WHERE i < 10;
GO

SELECT OBJECT_ID('dbo.my_proc2');
GO

<强> DB Fiddle

在这种情况下，object_id保持不变。

此示例方案可能会导致一些问题。我们假设我们使用SQL Server 2016 Query Store并强制对存储过程使用特定的查询计划。

DROP-CREATE

USE T1;
GO
-- make sure that Query Store is READ_WRITE 
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[a]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[a](
    [i] [int] IDENTITY(1,1) NOT NULL PRIMARY KEY,
    [g] [uniqueidentifier] NULL,
    [z] VARCHAR(10)
);
END
GO

-- populate table (15k records)
INSERT INTO dbo.a(g, z)
SELECT NEWID(), number
FROM (SELECT CAST([key] AS INT) AS number 
    FROM OPENJSON( '[1' + REPLICATE(',1',3000-1)+']')
    ) AS num
GO 5

-- initial creation
CREATE PROCEDURE dbo.my_proc
AS
SELECT *
FROM dbo.a
WHERE z LIKE '12%'
AND 1 = (SELECT 1);
GO

-- Clustered Index Scan
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 

SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
GO
--dc1

-- creating index
CREATE NONCLUSTERED INDEX IX_dbo_a_z
ON dbo.a([z] ASC) INCLUDE ([i], [g]);
GO

-- index seek
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 

SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;

-- forcing plan GUI, clustered scan
-- dc3

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
-- dc4

-- Clustered Index Scan
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
-- dc5

/* MAIN PART  - DROP - RECREATE */
DROP PROCEDURE IF EXISTS dbo.my_proc;
GO

CREATE PROCEDURE dbo.my_proc
AS
-- some meaningless comment added by developer
SELECT *
FROM dbo.a
WHERE z LIKE '12%'
AND 1 = (SELECT 1);
GO

/* MAIN PART END */

-- Index Seek
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
-- object_id in query store is NULL
-- is_forced_plan flag is ignored !!!

首次执行：

添加索引并执行：

强迫计划：

另一个执行：

DROP-CREATE之后：

创建 - 更改

USE T2;
GO
-- make sure that Query Store is READ_WRITE 
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[a]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[a](
    [i] [int] IDENTITY(1,1) NOT NULL PRIMARY KEY,
    [g] [uniqueidentifier] NULL,
    [z] VARCHAR(10)
);
END
GO

-- populate table (15k records)
INSERT INTO dbo.a(g, z)
SELECT NEWID(), number
FROM (SELECT CAST([key] AS INT) AS number 
    FROM OPENJSON( '[1' + REPLICATE(',1',3000-1)+']')
    ) AS num
GO 5

-- initial creation
CREATE PROCEDURE dbo.my_proc
AS
SELECT *
FROM dbo.a
WHERE z LIKE '12%'
AND 1 = (SELECT 1);
GO

-- Clustered Index Scan
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
-- ca1
GO

-- creating index
CREATE NONCLUSTERED INDEX IX_dbo_a_z
ON dbo.a([z] ASC) INCLUDE ([i], [g]);
GO

-- index seek
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
--ca2

-- forcing plan GUI
--ca3

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
--ca4

-- Clustered Index Scan
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;
--ca5
GO

/* MAIN PART  - CREATE-ALTER */
CREATE OR ALTER PROCEDURE dbo.my_proc
AS
-- some meaningless comment added by developer
SELECT *
FROM dbo.a
WHERE z LIKE '12%'
AND 1 = (SELECT 1);
GO

/* MAIN PART END */

-- Clustered Index Scan
EXEC dbo.my_proc;

EXEC sp_query_store_flush_db; 
SELECT qsq.query_id,
    qsq.query_text_id,
    qsq.context_settings_id,
    qsq.[object_id],
    OBJECT_NAME(qsq.[object_id]) AS [object_name],
    qsp.is_forced_plan,
    qsqt.query_sql_text,
    qsrs.count_executions,
    CAST(qsp.query_plan AS XbML) AS sql_query_plan
FROM sys.query_store_query qsq
JOIN sys.query_store_query_text qsqt
ON qsq.query_text_id = qsqt.query_text_id
JOIN sys.query_store_plan qsp
ON qsq.query_id= qsp.query_id
JOIN sys.query_store_runtime_stats qsrs
ON qsrs.plan_id = qsp.plan_id
WHERE query_sql_text LIKE '%dbo.a%'
AND qsq.[object_id] <> 0
ORDER BY qsq.query_id;

-- is_forced_plan is valid

首次执行：

添加索引并执行：

强迫计划：

另一个执行：

CREATE-ALTER之后：

结果

使用Drop-Create，我们失去了强制计划。

Answer 11

我有一个模板，允许多次执行脚本而不会出错。

IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[aaa_test]') AND type in (N'P', N'PC'))
    EXEC('CREATE PROCEDURE aaa_test AS')
    EXEC('GRANT EXECUTE ON aaa_test TO someone')
GO

ALTER PROCEDURE aaa_test 
     @PAR1 INT,
     @PAR2 INT=0
AS
BEGIN
    SELECT @PAR1 AS Par1, CASE @PAR2 WHEN 0 THEN 'Default' ELSE 'Other' END AS Par2
END
GO

执行：

EXEC aaa_test 1
EXEC aaa_test 1,5

Answer 12

你不应该放弃一个物体。删除对象会遇到两个问题：

1）如果CREATE失败，则不再有对象。（您可以使用事务来避免这种情况，代价是大量的样板代码）

2）如果您没有明确地重新创建对象，则会失去对该对象的权限。

我更喜欢在＆＃34;中创建一个空白对象;如果不存在＆＃34;条件，然后使用ALTER，并为此目的编写了帮助程序。

Answer 13

年份是2017年，SQL Server已创建或更改

SQL Server 2016 SP1和SQL Server vNext具有新的T-SQL语言声明 - 创建[或更改] ：

STOREDPROCEDURES
功能
TRIGGERS
视图

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2016/11/17/create-or-alter-another-great-language-enhancement-in-sql-server-2016-sp1/

Answer 14

到我的extend previous answer。

我更喜欢CREATE-ALTER超过DROP-CREATE方法的另一个原因。它可能导致丢失有关对象的特定属性。例如ExecIsStartup：

USE master
GO

CREATE TABLE dbo.silly_logging(id INT IDENTITY(1,1) PRIMARY KEY
                               ,created_date DATETIME DEFAULT GETDATE()
                               ,comment VARCHAR(100));
GO

CREATE PROCEDURE dbo.my_procedure 
AS
INSERT INTO dbo.silly_logging(comment)
VALUES ('SQL Server Startup');
GO

-- mark procedure to start at SQL Server instance startup
EXEC sp_procoption @ProcName = 'dbo.my_procedure'
    , @OptionName = 'startup'   
    , @OptionValue = 'on';


SELECT name, create_date, modify_date, is_auto_executed
FROM master.sys.procedures
WHERE is_auto_executed = 1;
--name  create_date modify_date is_auto_executed
--my_procedure  2017-07-28 06:36:21.743 2017-07-28 06:36:24.513 1

现在让我们假设有人想要使用DROP-CREATE更新此过程：

DROP PROCEDURE dbo.my_procedure;
GO

CREATE PROCEDURE dbo.my_procedure 
AS
-- adding meaningless comment
INSERT INTO dbo.silly_logging(comment)
VALUES ('SQL Server Startup');
GO

SELECT name, create_date, modify_date, is_auto_executed
FROM master.sys.procedures
WHERE is_auto_executed = 1;
-- empty

如果您没有意识到这一点，或者您没有检查，那么您最终会得到一个不会开始的程序。

你在SQL Server中做什么来创建或改变？

14 个答案:

DROP-CREATE

创建 - 更改

结果