我有一个在“位置A”中被更改的查找数据表,我需要更新“位置B”中相同的命名表。我在想,如果我有一种方法将表(80k行)逐行读入格式正确的字符串,并使用merge语句创建/的输出文件(将表“转换”为CTE),那么我就可以做一些巧妙的事情。
所有关于这个想法的想法(或者那些已经做过类似事情的人的建议)都是值得赞赏的。谢谢。我正在使用SQL Server Express 2012。
发布于 2012-05-08 06:01:48
我使用这个助手脚本来管理环境之间的小型查找表。80k行无论如何都不算大,但也不是微不足道。Conrad设计了一个用于移动大量数据的solid plan。
如果您确实选择使用生成的合并路线,希望这会对您有所帮助:
declare @TableName nvarchar(128) = 'dbo.YourTable';
--// do not modify
set nocount on;
if ( isnull(parsename(@TableName, 1), '') = '' or
isnull(parsename(@TableName, 2), '') = ''
)
begin
raiserror('@TableName should be in form of owner.object (dbo.Yak). Cannot continue.', 16, 1, @TableName);
return;
end
if object_id(@TableName) is null
begin
raiserror('Table [%s] not found. Cannot continue.', 16, 1, @TableName);
return;
end
if objectproperty(object_id(@TableName), N'TableHasPrimaryKey') = 0
begin
raiserror('Table [%s] has no primary key defined. Cannot continue.', 16, 1, @TableName);
return;
end
declare @output varchar(max)='', @return int, @sql varchar(max) = '', @list varchar(max) = '', @exec nvarchar(max), @Cols varchar(max)='',
@sCols varchar(max)='', @aCols varchar(max)='', @pCols varchar(max)='', @uCols varchar(max)='',
@b char(1) = char(13), @t char(1) = char(9);
select @exec = isnull(@exec + '+' + @b,'') + ''','' +' +
case
when c.data_type in ('uniqueidentifier')
then @t + '''''+isnull('''''''' + convert(varchar(50),' + c.column_name + ') + '''''''',''null'')'
when c.data_type in ('xml')
then @t + '''''+isnull('''''''' + convert(varchar(max),' + c.column_name + ') + '''''''',''null'')'
when c.data_type in ('char', 'nchar', 'varchar', 'nvarchar', 'sysname')
then @t + '''''+isnull('''''''' + replace(' + c.column_name + ','''''''','''''''''''') + '''''''',''null'')'
when c.data_type in ('datetime', 'date')
then @t + '''''+isnull('''''''' + convert(varchar,' + c.column_name + ',121)+'''''''',''null'') '
when c.data_type in ('tinyint', 'int', 'float', 'numeric', 'decimal', 'smallmoney', 'money', 'bit', 'smallint', 'real', 'bigint')
then @t + '''''+isnull(convert(varchar,' + c.column_name + '),''null'')'
else ''' ** data type [' + c.data_type + '] not supported **'''
end,
@Cols = @Cols + ','+quotename(c.column_name, '['),
@sCols = @sCols + ',s.'+quotename(c.column_name, '[')
from information_schema.columns c
where c.table_name = parsename(@TableName, 1) and
c.table_schema = parsename(@TableName, 2)
order
by c.ordinal_position
-- stage primary key columns
declare @pks table (c varchar(100), o int);
insert into @pks (c,o)
select kcu.column_name, kcu.ordinal_position
from information_schema.table_constraints tc
join information_schema.key_column_usage kcu on
tc.table_name = kcu.table_name and
tc.constraint_name = kcu.constraint_name
where tc.table_name = parsename(@TableName, 1) and
tc.table_schema = parsename(@TableName, 2) and
tc.constraint_type = 'PRIMARY KEY';
-- build primary key columns (1=1 to ease support of composite PKs)
set @pCols = '1=1'
select @pCols = @pCols + ' and '+isnull('t.'+quotename(c, '[') + ' = ' + 's.'+quotename(c, '['), '')
from @pks
order
by o;
-- build update columns, do not update identities or pks
select @aCols = @aCols + ','+quotename(c.[name], '[') + ' = s.' + quotename(c.[name], '[')
from sys.columns c
where object_id = object_id(@TableName) and
[name] not in (select c from @pks) and
columnproperty(object_id(@TableName), c.[name], 'IsIdentity ') = 0;
-- script the data out as table value constructors
select @exec = 'set nocount on; Select ' + @b + '''(' + ''' + ' + @b + stuff(@exec,1, 3, '') + '+'')''' + @b + 'from ' + @TableName,
@Cols = stuff(@Cols,1, 1, ''),
@sCols = stuff(@sCols,1, 1, ''),
@aCols = stuff(@aCols,1, 1, '');
declare @tab table (val varchar(max));
declare @Values varchar(max);
insert into @tab
exec(@exec);
if not exists(select 1 from @tab)
begin
raiserror('Table %s is valid but empty. Populate it before running this helper.', 16, 1, @TableName);
return
end
select @Values = stuff(cast((select ','+ @b + val from @tab for xml path('')) as xml).value('.', 'varchar(max)'),1,2,'');
-- build the merge statement
set @output += @b+'--'+@TableName+replicate('-', 98-len(@TableName))+@b+replicate('-', 100)+@b;
set @output += 'set nocount on;'+@b
if objectproperty(object_id(@TableName), 'TableHasIdentity') = 1
set @output += 'set identity_insert ['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] on;'+@b;
set @output += ';with cte_data('+@Cols+')'+@b+'as (select * from (values'+@b+'--'+replicate('/', 98) + @b +@Values+ @b +'--'+replicate('\', 98)+ @b +')c('+@Cols+'))'+@b;
set @output += 'merge' + @t + '['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] as t' + @b + 'using' + @t + 'cte_data as s'+@b;
set @output += 'on' + replicate(@t, 2) + @pCols+@b;
set @output += 'when matched then' + @b+@t + 'update set'+ @b+@t + @aCols+@b;
set @output += 'when not matched by target then'+@b;
set @output += @t+'insert(' + @Cols + ')'+@b;
set @output += @t+'values(' + @sCols + ')'+@b;
set @output += 'when not matched by source then' + @b+@t+ 'delete;'+@b;
if objectproperty(object_id(@TableName), 'TableHasIdentity') = 1
set @output += 'set identity_insert ['+parsename(@TableName, 2)+'].[' + parsename(@TableName, 1) + '] off;'
--output the statement as xml (to overcome mgmt studio limitations)
select s as [output] from (select @output)d(s) for xml path('');
return;
https://stackoverflow.com/questions/10489184
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