Sql 添加之前，请检查扩展属性描述是否已存在
因此，我有一个添加扩展属性的脚本，一些描述表，一些描述列。如何在添加扩展属性之前检查它是否存在，以便脚本不会引发错误？第一个脚本检查描述表的扩展属性是否存在：Sql 添加之前，请检查扩展属性描述是否已存在,sql,sql-server,exists,extended-properties,database-table,Sql,Sql Server,Exists,Extended Properties,Database Table,因此，我有一个添加扩展属性的脚本，一些描述表，一些描述列。如何在添加扩展属性之前检查它是否存在，以便脚本不会引发错误？第一个脚本检查描述表的扩展属性是否存在： IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES WHERE [major_id] = OBJECT_ID('Table_Name') AND [name] = N'MS_Description' AND [minor_id] = 0) EXECUTE sp_addextend
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES WHERE [major_id] = OBJECT_ID('Table_Name') AND [name] = N'MS_Description' AND [minor_id] = 0)
EXECUTE sp_addextendedproperty @name = N'MS_Description', @value = N'This table is responsible for holding information.', @level0type = N'SCHEMA', @level0name = N'dbo', @level1type = N'TABLE', @level1name = N'Table_Name';
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES WHERE [major_id] = OBJECT_ID('Table_Name') AND [name] = N'MS_Description' AND [minor_id] = (SELECT [column_id] FROM SYS.COLUMNS WHERE [name] = 'Column_Name' AND [object_id] = OBJECT_ID('Table_Name')))
EXECUTE sp_addextendedproperty @name = N'MS_Description', @value = N'This column is responsible for holding information for table Table_Name.', @level0type = N'SCHEMA', @level0name = N'dbo', @level1type = N'TABLE', @level1name = N'Table_Name', @level2type = N'COLUMN', @level2name = N'Column_Name';
要检查可用于给定表的任何扩展属性，请按如下所示使用
IF EXISTS(SELECT 1 FROM sys.extended_properties WHERE [major_id] = OBJECT_ID('<schema>.<table_name>') AND [name] = N'MS_Description')
有关更多详细信息，请使用我编写了一个简单的存储过程来添加或更新扩展属性“MS_Description”：
IF OBJECT_ID ('dbo.usp_addorupdatedescription', 'P') IS NOT NULL
DROP PROCEDURE dbo.usp_addorupdatedescription;
GO
CREATE PROCEDURE usp_addorupdatedescription
@table nvarchar(128), -- table name
@column nvarchar(128), -- column name, NULL if description for table
@descr sql_variant -- description text
AS
BEGIN
SET NOCOUNT ON;
DECLARE @c nvarchar(128) = NULL;
IF @column IS NOT NULL
SET @c = N'COLUMN';
BEGIN TRY
EXECUTE sp_updateextendedproperty N'MS_Description', @descr, N'SCHEMA', N'dbo', N'TABLE', @table, @c, @column;
END TRY
BEGIN CATCH
EXECUTE sp_addextendedproperty N'MS_Description', @descr, N'SCHEMA', N'dbo', N'TABLE', @table, @c, @column;
END CATCH;
END
GO
下面是另一种存储过程方法，类似于Ruslan K.的方法，但不涉及try/catch或显式事务：
-- simplify syntax for maintaining data dictionary
IF OBJECT_ID ('dbo.usp_addorupdatedescription', 'P') IS NOT NULL
DROP PROCEDURE dbo.usp_addorupdatedescription;
GO
CREATE PROCEDURE usp_addorupdatedescription
@table nvarchar(128), -- table name
@column nvarchar(128), -- column name, NULL if description for table
@descr sql_variant -- description text
AS
BEGIN
SET NOCOUNT ON;
IF @column IS NOT NULL
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES
WHERE [major_id] = OBJECT_ID(@table) AND [name] = N'MS_Description'
AND [minor_id] = (SELECT [column_id]
FROM SYS.COLUMNS WHERE [name] = @column AND [object_id] = OBJECT_ID(@table)))
EXECUTE sp_addextendedproperty @name = N'MS_Description', @value = @descr,
@level0type = N'SCHEMA', @level0name = N'dbo', @level1type = N'TABLE',
@level1name = @table, @level2type = N'COLUMN', @level2name = @column;
ELSE
EXECUTE sp_updateextendedproperty @name = N'MS_Description',
@value = @descr, @level0type = N'SCHEMA', @level0name = N'dbo',
@level1type = N'TABLE', @level1name = @table,
@level2type = N'COLUMN', @level2name = @column;
ELSE
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES
WHERE [major_id] = OBJECT_ID(@table) AND [name] = N'MS_Description'
AND [minor_id] = 0)
EXECUTE sp_addextendedproperty @name = N'MS_Description', @value = @descr,
@level0type = N'SCHEMA', @level0name = N'dbo',
@level1type = N'TABLE', @level1name = @table;
ELSE
EXECUTE sp_updateextendedproperty @name = N'MS_Description', @value = @descr,
@level0type = N'SCHEMA', @level0name = N'dbo',
@level1type = N'TABLE', @level1name = @table;
END
GO
也许我的回答没有直接联系到这个问题，但我想指出的是，MS_描述实际上是区分大小写的，即使我们用SQL添加它。如果我们使用MS_描述而不是MS_描述，它将不会显示在SMSS表设计视图中 在我的例子中，我必须这样做来删除现有的描述并添加一个正确的描述
IF EXISTS (
SELECT NULL
FROM SYS.EXTENDED_PROPERTIES
WHERE [major_id] = OBJECT_ID('TableName')
AND [name] = N'MS_DESCRIPTION'
AND [minor_id] = (
SELECT [column_id]
FROM SYS.COLUMNS
WHERE [name] = 'ColumnName'
AND [object_id] = OBJECT_ID('Tablename')
)
)
EXEC sys.sp_dropextendedproperty @name = N'MS_DESCRIPTION'
,@level0type = N'SCHEMA'
,@level0name = N'dbo'
,@level1type = N'TABLE'
,@level1name = N'TableName'
,@level2type = N'COLUMN'
,@level2name = N'ColumnName'
GO
EXEC sys.sp_addextendedproperty @name = N'MS_Description'
,@value = N'Description detail'
,@level0type = N'SCHEMA'
,@level0name = N'dbo'
,@level1type = N'TABLE'
,@level1name = N'TableName'
,@level2type = N'COLUMN'
,@level2name = N'ColumnName'
GO请查找我对上面Brian Westrich答案的扩展，但此版本允许更新和添加表和列上的任何扩展属性，而不仅仅是MS_描述。此外，它还允许您使用存储过程在不同的数据库中添加和更新扩展属性，以便在服务器上只需要一个副本
CREATE PROCEDURE dbo.AddOrUpdateExtendedProperty
@Database NVARCHAR(128) -- Database name
,@Schema NVARCHAR(128) -- Schema name
,@Table NVARCHAR(128) -- Table name
,@Column NVARCHAR(128) -- Column name, NULL if description for table
,@PropertyName NVARCHAR(128) -- Property name
,@PropertyValue SQL_VARIANT -- Property value
AS
BEGIN
SET NOCOUNT ON;
DECLARE @NSQL NVARCHAR(MAX);
DECLARE @Level2Type NVARCHAR(128) = NULL;
DECLARE @Params NVARCHAR(MAX) = N'@Schema NVARCHAR(128), @Table NVARCHAR(128), @Column NVARCHAR(128), @PropertyName NVARCHAR(128), @PropertyValue SQL_VARIANT';
IF @Column IS NOT NULL
BEGIN
SET @NSQL = 'USE ' + @Database + ';
IF NOT EXISTS
(
SELECT NULL FROM sys.extended_properties
WHERE major_id = OBJECT_ID(''' + @Schema + '.' + @Table + ''')
AND name = @PropertyName
AND minor_id = (SELECT column_id
FROM sys.columns
WHERE name = @Column
AND object_id = OBJECT_ID(''' + @Schema + '.' + @Table + ''')
)
)
BEGIN
EXECUTE sp_addextendedproperty
@name = @PropertyName
,@value = @PropertyValue
,@level0type = N''SCHEMA''
,@level0name = @Schema
,@level1type = N''TABLE''
,@level1name = @Table
,@level2type = N''COLUMN''
,@level2name = @Column;
END
ELSE
BEGIN
EXECUTE sp_updateextendedproperty
@name = @PropertyName
,@value = @PropertyValue
,@level0type = N''SCHEMA''
,@level0name = @Schema
,@level1type = N''TABLE''
,@level1name = @Table
,@level2type = N''COLUMN''
,@level2name = @Column;
END
';
EXECUTE sp_executesql
@NSQL
,@Params
,@Schema
,@Table
,@Column
,@PropertyName
,@PropertyValue;
END
ELSE
BEGIN
SET @NSQL = 'USE ' + @Database + ';
IF NOT EXISTS
(
SELECT NULL
FROM sys.extended_properties
WHERE major_id = OBJECT_ID(''' + @Schema + '.' + @Table + ''')
AND name = @PropertyName
AND minor_id = 0
)
BEGIN
EXECUTE sp_addextendedproperty
@name = @PropertyName
,@value = @PropertyValue
,@level0type = N''SCHEMA''
,@level0name = @Schema
,@level1type = N''TABLE''
,@level1name = @Table;
END
ELSE
BEGIN
EXECUTE sp_updateextendedproperty
@name = @PropertyName
,@value = @PropertyValue
,@level0type = N''SCHEMA''
,@level0name = @Schema
,@level1type = N''TABLE''
,@level1name = @Table;
END
';
EXECUTE sp_executesql
@NSQL
,@Params
,@Schema
,@Table
,@Column
,@PropertyName
,@PropertyValue;
END
END
基于ScubaSteve的回答，以下查询将允许您按名称检查指定架构内的列或表上的MS_Description属性。要检查表，只需将谓词c.name=替换为c.name IS NULL或d.minor_id=0即可 要按架构枚举MS_描述属性，请使用-
SELECT a.name as [schema], b.name as [table], c.name as [column], d.name, d.value
FROM sys.schemas a
JOIN sys.tables b ON a.schema_id = b.schema_id
LEFT JOIN sys.columns c ON b.object_id = c.object_id
JOIN sys.extended_properties d ON d.major_id = b.object_id AND d.minor_id = ISNULL(c.column_id,0)
WHERE a.name = '<schema>' AND b.name = '<table>' AND c.name = '<column>' AND d.name = 'MS_Description'
IF NOT EXISTS (SELECT 1 FROM sys.schemas a JOIN sys.tables b ON a.schema_id = b.schema_id LEFT JOIN sys.columns c ON b.object_id = c.object_id JOIN sys.extended_properties d ON d.major_id = b.object_id AND d.minor_id = ISNULL(c.column_id,0)
WHERE a.name = '<schema>' AND b.name = '<table>' AND c.name = '<column>' AND d.name = 'MS_Description'
)
BEGIN
--EXEC sp_addextendedproperty statement goes here
END
这些查询中的连接可能可以更好地排序，以消除ISNULL函数，但这应该可以满足您的要求。我喜欢这种方法，但是我遇到了一个实例，在执行此查询后，我有一个打开的事务。``Msg 266，16级，状态2，Procedure up_DATADECT，第178行EXECUTE后的事务计数表示BEGIN和COMMIT语句的数量不匹配。上一次计数=0，当前计数=1```我在下面发布了一个类似的方法，它不使用try/catch，事务回滚也不那么优雅，但避免了DamianUsage提出的问题。但是，使用异常处理来控制程序流，即使用IF语句可以做什么，这是一个错误！。看这个。。。一般来说，至少在历史上，只要问题/答案提供价值，那么SO允许这样做。我相信，他们确实要求你在接受自己的答案之前提供一些时间，让其他人也回答，并且客观地选择最佳答案，而不仅仅是将自己的答案标记为正确以获得+代表。因此这很好，唯一令人担心的是，人们在接受自己的答案之前，没有给其他人时间提供答案。重要提示：如果在同一数据库中有两个名称相同但模式不同的表，则If条件将失败。如果我不是SQL Server硬用户，我将尝试找到一种方法来指定该条件的模式，我将在这里分享我的发现。
IF NOT EXISTS (SELECT 1 FROM sys.schemas a JOIN sys.tables b ON a.schema_id = b.schema_id LEFT JOIN sys.columns c ON b.object_id = c.object_id JOIN sys.extended_properties d ON d.major_id = b.object_id AND d.minor_id = ISNULL(c.column_id,0)
WHERE a.name = '<schema>' AND b.name = '<table>' AND c.name = '<column>' AND d.name = 'MS_Description'
)
BEGIN
--EXEC sp_addextendedproperty statement goes here
END