动态sql查询语法不正确

Question

我需要有关动态 sql 查询的帮助。 现在，我的查询是这样的

declare @query nvarchar(MAX), @preSubQuery nvarchar(200), @subQueryTxt nvarchar(500), @postSubQuery nvarchar(100);
set @postSubQuery = N' ELSE 0 END))'
set @preSubQuery = N' ,SUM(( CASE DATEDIFF(WEEK, pay.dateCreate, back.dateCreate) WHEN ';
set @subQueryTxt = N' THEN
                    CASE
                        WHEN ...
                            THEN 0
                        WHEN ...
                            THEN ...
                        ELSE
                            CASE
                                WHEN ...
                                    THEN ...
                                WHEN ...
                                    THEN ...
                                ELSE 0
                            END
                    END ';

select @query = N'select DATEPART(ISO_WEEK, pay.dateCreate) backWeek ,SUM(pay_and_back.PayActualPrincipalAmt) AS TotalAmount' +
+ N' @preSubQuery' + N' 0' + ' @subQueryTxt' + ' @postSubQuery'
+ N' @preSubQuery' + N' 1' + ' @subQueryTxt' + ' @postSubQuery'
+ N' @preSubQuery' + N' 2' + ' @subQueryTxt' + ' @postSubQuery'
....
+ N' @preSubQuery' + N' 12' + ' @subQueryTxt' + ' @postSubQuery'
select @query = @query +    N'
from FinDocPayToPayback pay_and_back
    left join FinDocument pay   on pay.id   = pay_and_back.PayID
    left join FinDocument back  on back.id  = pay_and_back.PaybackID
    group by DATEPART(ISO_WEEK, pay.dateCreate) order by 1';

    select @query

EXECUTE sp_executesql @query
                        ,N'@preSubQuery nvarchar(200)', @preSubQuery
                        ,N'@subQueryTxt nvarchar(500)', @subQueryTxt
                        ,N'@postSubQuery nvarchar(100)', @postSubQuery;

但我收到错误 Incorrect syntax。首先，我需要有关此查询的帮助。第二， 谁能提供更多关于如何构建复杂动态查询的信息？

Answer 1

这是你的问题。介于.... 之间的某个位置会导致问题。

每次可以使用print @query，无论何时卡住或出错。

declare @query nvarchar(MAX), @preSubQuery nvarchar(200), @subQueryTxt nvarchar(500), @postSubQuery nvarchar(100);
set @postSubQuery = N' ELSE 0 END))'
set @preSubQuery = N' ,SUM(( CASE DATEDIFF(WEEK, pay.dateCreate, back.dateCreate) WHEN ';
set @subQueryTxt = N' THEN
                    CASE
                        WHEN ...
                            THEN 0
                        WHEN ...
                            THEN ...
                        ELSE
                            CASE
                                WHEN ...
                                    THEN ...
                                WHEN ...
                                    THEN ...
                                ELSE 0
                            END
                    END ';

select @query = N'select DATEPART(ISO_WEEK, pay.dateCreate) backWeek ,SUM(pay_and_back.PayActualPrincipalAmt) AS TotalAmount' +
+ N' @preSubQuery' + N' 0' + ' @subQueryTxt' + ' @postSubQuery'
+ N' @preSubQuery' + N' 1' + ' @subQueryTxt' + ' @postSubQuery'
+ N' @preSubQuery' + N' 2' + ' @subQueryTxt' + ' @postSubQuery'

+ N' @preSubQuery' + N' 12' + ' @subQueryTxt' + ' @postSubQuery'
select @query = @query +    N'
from FinDocPayToPayback pay_and_back
    left join FinDocument pay   on pay.id   = pay_and_back.PayID
    left join FinDocument back  on back.id  = pay_and_back.PaybackID
    group by DATEPART(ISO_WEEK, pay.dateCreate) order by 1';

    select @query

这是执行时上述查询的实际输出

 SELECT    Datepart(iso_week, pay.datecreate)         backweek ,
          Sum(pay_and_back.payactualprincipalamt) AS totalamount @preSubQuery 0 @subQueryTxt @postSubQuery @preSubQuery 1 @subQueryTxt @postSubQuery @preSubQuery 2 @subQueryTxt @postSubQuery @preSubQuery 12 @subQueryTxt @postSubQuery
FROM      findocpaytopayback pay_and_back
LEFT JOIN findocument pay
ON        pay.id = pay_and_back.payid
LEFT JOIN findocument back
ON        back.id = pay_and_back.paybackid
GROUP BY  datepart(iso_week, pay.datecreate)
ORDER BY  1 

对于复杂的动态查询，这是要理解的示例。 示例 1

--declare table1 table ( id int, value varchar(10) )
--drop table Table1
begin tran
create table table1 ( id int, value varchar(10) )
insert into table1 values( 1,'001')
insert into table1 values(2, '002')
insert into table1 values( 3,'003')
insert into table1 values( 4,'004')

create table table2 ( id int, value varchar(10) )
insert into table2 values( 1,'t2value1')
insert into table2 values(2, 't2value2')
insert into table2 values( 3,'t2value3')
insert into table2 values( 4,'t2value4')

-----1st example
declare @sql nvarchar(max) , @temp varchar(50) = '1,2,3'
select * from table1
set @sql = 'select * from table1 where id in ( ' + @temp + ')'

declare @join_table varchar(max)= 'table2', @whereCondition varchar(max) = ' where ' , @orderby varchar(max) = ' t1.id'
select @sql
exec sp_executesql @sql

-----2nd example
set @sql = 'select * from table1 t1 inner join ' + @join_table + ' t2 on t1.id = t2.id '

--if @parameter != null  you can give above this condition for
    set @whereCondition = @whereCondition + ' t1.id in ( ' + @temp + ')' 

    --if @orderby != null order by  condition
    set @orderby = ' order by '+ @orderby

    set @sql = @sql + @whereCondition + @orderby

    select @sql  --you can check that what is wrong by 

exec sp_executesql @sql

rollback

**Example2 : 将参数传递给动态查询**

--begin tran
--create table table1 ( id int, value varchar(10) )
--insert into table1 values( 1,'001')
--insert into table1 values(2, '002')
--insert into table1 values( 3,'003')
--insert into table1 values( 4,'004')

declare @sql nvarchar(max) , @temp nvarchar(50) = '1,2,3', @tempIntSingleValue nvarchar(50) = '2'
select * from table1

set @sql = 'select * from table1 where id in ( ' + @temp + ')'
print @sql
exec sp_executesql @sql 

set @sql = 'select * from table1 where id in ( @tempInner)'
print @sql
exec sp_executesql @sql , N'@tempInner int', @tempInner = @tempIntSingleValue

--rollback