SqlServer 批量修改某个字段类型

--drop table #tmp_table

SELECT name into #tmp_table FROM SysObjects Where XType='U' 
declare @table nvarchar(50)
while exists (select top 1 * from #tmp_table)
BEGIN
    select top 1 @table = name from #tmp_table
    if Exists (SELECT * FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME=@table and COLUMN_NAME='SyncError')
    BEGIN
        declare @SQL NVARCHAR(200)= 'ALTER TABLE ' + @table +
        ' ALTER COLUMN SyncError NVARCHAR(MAX);'
        exec(@sql)

    END
    delete from #tmp_table where name=@table

END