我想知道是否可以实现以下目标:
ALTER TABLE dbo.[Foo]
ALTER COLUMN * NVARCHAR(500)
WHERE Columns NVARCHAR(n) < NVARCHAR(500);
您可以使用information_schema.columns
并构建一个动态sql查询来生成查询。仍然需要复制结果并手动运行它们。
select 'alter table '+TABLE_SCHEMA+'.'+TABLE_NAME+' alter column '+COLUMN_NAME+' NVARCHAR(500)'
from INFORMATION_SCHEMA.columns
where DATA_TYPE = 'nvarchar'
and CHARACTER_MAXIMUM_LENGTH < 500
and table_name = 'foo'
and TABLE_SCHEMA = 'dbo'
在下方编辑
使用以下代码包括null
/not null
select 'alter table ['+TABLE_SCHEMA+'].['+TABLE_NAME+'] alter column ['+COLUMN_NAME+'] NVARCHAR(500) '+case when IS_NULLABLE = 'YES' then 'NULL' else 'NOT NULL' end
from INFORMATION_SCHEMA.columns
where DATA_TYPE = 'nvarchar'
and CHARACTER_MAXIMUM_LENGTH < 500
and table_name = 'foo'
and TABLE_SCHEMA = 'dbo'