帮我写一个SQL语句 要求为查询USER_CONSTRAINTS视图,确认约束已被添加,注意约束的类型和名字。将 语句文本保存到文件lab10_4.sql中。
时间: 2024-03-07 21:47:49 浏览: 19
好的,以下是查询USER_CONSTRAINTS视图的SQL语句:
```
SELECT constraint_name, constraint_type
FROM user_constraints;
```
这条语句将返回用户的所有约束(包括主键、外键、唯一约束、检查约束等)的名称和类型。您可以根据需要添加WHERE子句来筛选特定的约束。执行完后,可以将查询结果保存到lab10_4.sql中。
相关问题
sqlserver通过语句 根据表生成建表语句及索引和约束的语句
在 SQL Server 中,可以使用以下语句生成表的建表语句:
```
SELECT
'CREATE TABLE ' +
schema_name(tab.schema_id) + '.' + tab.name + '(' +
column_list +
CASE WHEN EXISTS (SELECT * FROM sys.indexes WHERE object_id = tab.object_id AND is_primary_key = 1) THEN ', CONSTRAINT ' + pk.name + ' PRIMARY KEY CLUSTERED (' + pk_col_list + ')' ELSE '' END +
')' +
CASE WHEN tab.create_date <> tab.modify_date THEN '/* Created: ' + CONVERT(NVARCHAR(30),tab.create_date,120) + ', Modified: ' + CONVERT(NVARCHAR(30),tab.modify_date,120) + ' */' ELSE '' END AS create_table_script
FROM sys.tables AS tab
CROSS APPLY (SELECT
STUFF((SELECT
', ' + col.name + ' ' + sys.types.name +
CASE WHEN col.is_nullable = 0 THEN ' NOT NULL' ELSE '' END +
CASE WHEN defn.definition IS NOT NULL THEN ' DEFAULT' + defn.definition ELSE '' END
FROM sys.columns AS col
JOIN sys.types ON col.user_type_id = sys.types.user_type_id
LEFT JOIN sys.default_constraints AS defn ON col.default_object_id = defn.object_id
WHERE col.object_id = tab.object_id
ORDER BY col.column_id
FOR XML PATH(''), TYPE).value('.', 'nvarchar(max)'), 1, 2, '')) AS column_list
LEFT JOIN (
SELECT
i.object_id,
name,
STUFF((SELECT
', ' + col.name
FROM sys.index_columns AS ic
JOIN sys.columns AS col ON ic.column_id = col.column_id AND ic.object_id = col.object_id
WHERE i.object_id = ic.object_id AND i.index_id = ic.index_id
ORDER BY ic.key_ordinal
FOR XML PATH(''), TYPE).value('.', 'nvarchar(max)'), 1, 2, '') AS pk_col_list
FROM sys.indexes AS i
WHERE is_primary_key = 1
) AS pk ON tab.object_id = pk.object_id
```
此语句将生成所有表的 CREATE TABLE 语句和主键约束。如果还需要生成索引和其他约束的语句,可以参考以下示例:
```
SELECT
'CREATE ' +
CASE WHEN is_unique_constraint = 1 THEN 'UNIQUE ' ELSE '' END +
'INDEX ' +
ix.name + ' ON ' +
schema_name(tab.schema_id) + '.' + tab.name + '(' +
STUFF((SELECT
', ' + col.name +
CASE WHEN ic.is_descending_key = 1 THEN ' DESC' ELSE '' END
FROM sys.index_columns AS ic
JOIN sys.columns AS col ON ic.column_id = col.column_id AND ic.object_id = col.object_id
WHERE ic.object_id = ix.object_id AND ic.index_id = ix.index_id
ORDER BY ic.key_ordinal
FOR XML PATH(''), TYPE).value('.', 'nvarchar(max)'), 1, 2, '') +
')' +
CASE WHEN ix.create_date <> ix.modify_date THEN '/* Created: ' + CONVERT(NVARCHAR(30),ix.create_date,120) + ', Modified: ' + CONVERT(NVARCHAR(30),ix.modify_date,120) + ' */' ELSE '' END AS create_index_script
FROM sys.indexes AS ix
JOIN sys.tables AS tab ON ix.object_id = tab.object_id
WHERE is_primary_key = 0 AND is_unique_constraint = 0 AND is_disabled = 0 AND ix.type <> 0
```
此语句将生成所有非聚集索引的 CREATE INDEX 语句。如果还需要生成其他约束的语句,可以使用类似的方法查询 sys.objects 和其他系统视图。
oracle 查看表约束语句
要查看Oracle表的约束语句,您可以查询系统视图`USER_CONSTRAINTS`或`ALL_CONSTRAINTS`。以下是一个示例查询:
```sql
SELECT CONSTRAINT_NAME, CONSTRAINT_TYPE, SEARCH_CONDITION
FROM USER_CONSTRAINTS
WHERE TABLE_NAME = 'your_table';
```
在上面的查询中,将"your_table"替换为您要查看约束的表名。该查询会返回与指定表相关的约束信息,包括约束名称(CONSTRAINT_NAME)、约束类型(CONSTRAINT_TYPE)和搜索条件(SEARCH_CONDITION)。
如果要查看所有者不是当前用户的表的约束,请使用`ALL_CONSTRAINTS`视图,并在查询中添加条件以指定表的所有者。
希望对您有所帮助!