SQL语句大小写是否区分的问题，批量修改整个数据库所有表所有字段大小写

declare @maco table (number int,myvalue varchar(2))

insert into @maco select 1,'aa' union all

select 2,'Aa' union all

select 3,'aA' union all

select 4,'AA'

--不区分大小写

select * from @maco WHERE nn='aa'

--区分大小写

select  * from @maco WHERE nn='aa' collate Chinese_PRC_CS_AI

--不区分大小写

ALTER TABLE My_table ALTER Column colname nvarchar(100) collate Chinese_PRC_CI_AS     

--区分大小写  

ALTER TABLE My_table ALTER Column colname nvarchar(100) collate Chinese_PRC_CS_AS

--不区分大小写  

ALTER DATABASE databasename collate Chinese_PRC_CI_AS    

--区分大小写   

ALTER DATABASE databasename collate Chinese_PRC_CS_AS  

DECLARE @collate nvarchar(100);
DECLARE @table nvarchar(255);
DECLARE @column_name nvarchar(255);
DECLARE @column_id int;
DECLARE @data_type nvarchar(255);
DECLARE @max_length int;
DECLARE @row_id int;
DECLARE @sql nvarchar(max);
DECLARE @sql_column nvarchar(max);
DECLARE @is_nullable int;
DECLARE @nullornot nvarchar(255);

SET @collate = 'Chinese_PRC_CS_AS'; --不区分大小写：  Chinese_PRC_CI_AS    区分大小写 ：Chinese_PRC_CS_AS

DECLARE local_table_cursor CURSOR FOR

SELECT [name]
FROM sysobjects
WHERE OBJECTPROPERTY(id, N'IsUserTable') = 1

OPEN local_table_cursor
FETCH NEXT FROM local_table_cursor
INTO @table

WHILE @@FETCH_STATUS = 0
BEGIN

    DECLARE local_change_cursor CURSOR FOR

    SELECT ROW_NUMBER() OVER (ORDER BY c.column_id) AS row_id
        , c.name column_name
        , t.Name data_type
        , c.max_length
        , c.column_id
		, c.is_nullable
    FROM sys.columns c
    JOIN sys.types t ON c.system_type_id = t.system_type_id
    LEFT OUTER JOIN sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
    LEFT OUTER JOIN sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
    WHERE c.object_id = OBJECT_ID(@table)
    ORDER BY c.column_id

    OPEN local_change_cursor
    FETCH NEXT FROM local_change_cursor
    INTO @row_id, @column_name, @data_type, @max_length, @column_id,@is_nullable

    WHILE @@FETCH_STATUS = 0
    BEGIN

        IF (@max_length = -1) OR (@max_length > 4000) SET @max_length = 4000;
		IF (@is_nullable = 1) SET @nullornot=' not null' ELSE SET @nullornot=''

        IF (@data_type LIKE '%char%')
        BEGIN TRY
            SET @sql = 'ALTER TABLE ' + @table + ' ALTER COLUMN ' + @column_name + ' ' + @data_type + '(' + CAST(@max_length AS nvarchar(100)) + ') COLLATE ' + @collate  +' ' +@nullornot
            PRINT @sql
            EXEC sp_executesql @sql
        END TRY
        BEGIN CATCH
          PRINT 'ERROR: Some index or constraint rely on the column ' + @column_name + '. No conversion possible.'
          PRINT @sql
        END CATCH

        FETCH NEXT FROM local_change_cursor
        INTO @row_id, @column_name, @data_type, @max_length, @column_id,@is_nullable

    END

    CLOSE local_change_cursor
    DEALLOCATE local_change_cursor

    FETCH NEXT FROM local_table_cursor
    INTO @table

END

CLOSE local_table_cursor
DEALLOCATE local_table_cursor

GO