Sql server 是否获取唯一约束列列表(在TSQL中)?
通过以下查询,我可以很容易地获得唯一约束的列表:Sql server 是否获取唯一约束列列表(在TSQL中)?,sql-server,tsql,metadata,constraints,Sql Server,Tsql,Metadata,Constraints,通过以下查询,我可以很容易地获得唯一约束的列表: select * from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='UNIQUE' 但是如何获得每个唯一约束应用于的列的列表呢?请参见信息\u架构。约束列的用法是正确的,这些列显示在约束列用法视图中,下面是它的SQL select TC.Constraint_Name, CC.Column_Name from information_schema.table_con
select * from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='UNIQUE'
但是如何获得每个唯一约束应用于的列的列表呢?请参见
信息\u架构。约束列的用法是正确的,这些列显示在约束列用法视图中,下面是它的SQL
select TC.Constraint_Name, CC.Column_Name from information_schema.table_constraints TC
inner join information_schema.constraint_column_usage CC on TC.Constraint_Name = CC.Constraint_Name
where TC.constraint_type = 'Unique'
order by TC.Constraint_Name
仅供mySQL用户参考,
通过以下查询也可以实现同样的效果:
查找表上的任何唯一约束的步骤
select * from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='UNIQUE' and table_name='db_my_table'
查找包含所有列的唯一列列表
select * from INFORMATION_SCHEMA.KEY_COLUMN_USAGE where CONSTRAINT_NAME='cons_name' and TABLE_NAME='db_my_table'
查找具有所需视图的唯一列列表
select CONSTRAINT_NAME,COLUMN_NAME,TABLE_NAME from INFORMATION_SCHEMA.KEY_COLUMN_USAGE where CONSTRAINT_NAME='cons_name' and TABLE_NAME='db_my_table'
巫术
信息\u SCHEMA.CONSTRAINT\u列\u的使用速度非常慢
使用sys.index,连接表、模式、对象,作为额外的奖励,您不仅可以获得唯一的约束,还可以获得唯一的索引,包括过滤器
-- CREATE TABLE dbo.T_User( USR_ID int NOT NULL, USR_User nvarchar(256) NULL, USR_Status int NOT NULL );
-- ALTER TABLE dbo.T_User ADD CONSTRAINT UC_T_User_USR_User UNIQUE(USR_User)
-- IF NOT EXISTS (SELECT * FROM sys.indexes WHERE object_id = OBJECT_ID(N'dbo.T_User') AND name = N'IX_T_User_USR_User')
-- CREATE UNIQUE INDEX IX_T_User_USR_User ON dbo.T_User(USR_User)
-- WHERE (USR_User IS NOT NULL AND USR_Status=(1))
SELECT
sch.name
,st.name
,i.name
,i.has_filter
,i.filter_definition
,i.is_unique
,i.is_primary_key
,i.is_unique_constraint
,CASE WHEN i.is_unique_constraint = 1
THEN N'ALTER TABLE ' + QUOTENAME(sch.name) + N'.' + QUOTENAME(st.name) + N' DROP CONSTRAINT ' + QUOTENAME(i.name) + N'; '
ELSE N'DROP INDEX ' + QUOTENAME(i.name) + N' ON ' + QUOTENAME(sch.name) + '.' + QUOTENAME(st.name) + '; '
END AS sql
FROM sys.indexes AS i
INNER JOIN sys.index_columns AS ic
ON i.index_id = ic.index_id
AND i.object_id = ic.object_id
INNER JOIN sys.tables AS st
ON st.object_id = i.object_id
INNER JOIN sys.objects AS syso
ON syso.object_id = st.object_id
AND syso.is_ms_shipped = 0
INNER JOIN sys.schemas AS sch
ON sch.schema_id = st.schema_id
WHERE (1=1)
AND NOT EXISTS
(
SELECT *
FROM sys.extended_properties AS xp
WHERE xp.minor_id = 0
AND xp.major_id = st.object_id
AND xp.name = 'microsoft_database_tools_support'
)
-- AND sch.name = 'dbo'
-- AND st.name = 'T_Benutzer'
AND
(
i.is_unique_constraint = 1
OR
(i.is_unique = 1 AND i.is_primary_key = 0)
)
;
下面是一个更好的解决方案,它以适当的排序顺序列出约束列,并添加了ASC/DESC标志。它还允许按目录、模式或表名进行筛选
SELECT sh.name AS schema_name,
i.name AS constraint_name,
t.name AS table_name,
c.name AS column_name,
ic.key_ordinal AS column_position,
ic.is_descending_key AS is_desc
FROM sys.indexes i
INNER JOIN sys.index_columns ic
ON i.index_id = ic.index_id AND i.object_id = ic.object_id
INNER JOIN sys.tables AS t
ON t.object_id = i.object_id
INNER JOIN sys.columns c
ON t.object_id = c.object_id AND ic.column_id = c.column_id
INNER JOIN sys.objects AS syso
ON syso.object_id = t.object_id AND syso.is_ms_shipped = 0
INNER JOIN sys.schemas AS sh
ON sh.schema_id = t.schema_id
INNER JOIN information_schema.schemata sch
ON sch.schema_name = sh.name
WHERE i.is_unique_constraint = 1
-- AND sch.catalog_name = 'EmployeesQX'
-- AND sh.name = 'dbo'
ORDER BY sh.name, i.name, ic.key_ordinal;
我使用filterconstraint\u type='check'
来检查约束,例如:其中TC.constraint\u type='check'和TC.TABLE\u NAME='Roles2016.UsersCRM'和CC.Column\u NAME='State'
不正确,可能在多个列上有唯一的约束。
SELECT sh.name AS schema_name,
i.name AS constraint_name,
t.name AS table_name,
c.name AS column_name,
ic.key_ordinal AS column_position,
ic.is_descending_key AS is_desc
FROM sys.indexes i
INNER JOIN sys.index_columns ic
ON i.index_id = ic.index_id AND i.object_id = ic.object_id
INNER JOIN sys.tables AS t
ON t.object_id = i.object_id
INNER JOIN sys.columns c
ON t.object_id = c.object_id AND ic.column_id = c.column_id
INNER JOIN sys.objects AS syso
ON syso.object_id = t.object_id AND syso.is_ms_shipped = 0
INNER JOIN sys.schemas AS sh
ON sh.schema_id = t.schema_id
INNER JOIN information_schema.schemata sch
ON sch.schema_name = sh.name
WHERE i.is_unique_constraint = 1
-- AND sch.catalog_name = 'EmployeesQX'
-- AND sh.name = 'dbo'
ORDER BY sh.name, i.name, ic.key_ordinal;