动态 SQL，参数化查询
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【中文标题】动态 SQL，参数化查询【英文标题】：Dynamic SQL, parameterized Query 【发布时间】：2017-08-04 17:58:06 【问题描述】：我编写了一个查询来提取 SQL AlwaysON 运行状况信息。剩下要做的就是在最后添加一个 where 子句来过滤 AvailabilityGroupName 和 DatabaseName。当我输入查询时它起作用：'select * from results where AvailabilityGroupName ='LAB-VIP-USADB' AND DatabaseName ='CPS''。但是，当我在开始时将查询存储在 nvarchar 变量 @sql 中并稍后执行存储在变量中的查询时，我收到错误消息“关键字'EXEC'附近的语法不正确”。我想参数化查询的原因是一个可用性组可以包含多个数据库。参数化输入将来自 PRTG，以便查询该特定数据库的可用性组。
DECLARE @sql NVARCHAR(MAX)
SET @sql='SELECT * FROM Results WHERE AvailabilityGroupName = ''LAB-VIP-USADB'' AND DatabaseName = ''CPS'''
--select @sql
;
WITH basicaginfo AS(
SELECT
ag.name AS AvailabilityGroupName,
cs.replica_server_name AS NodeName,
rs.role_desc,
rs.synchronization_health_desc,
DB_NAME(drs.database_id) AS DatabaseName
FROM
sys.availability_groups ag
JOIN
sys.dm_hadr_availability_replica_cluster_states cs on ag.group_id = cs.group_id
JOIN
sys.dm_hadr_availability_replica_states rs ON (ag.group_id=rs.group_id AND cs.replica_id = rs.replica_id)
JOIN
sys.dm_hadr_database_replica_states drs ON (ag.group_id=drs.group_id AND cs.replica_id = drs.replica_id)
),
AG_Stats AS
(
SELECT AR.replica_server_name,
HARS.role_desc,
Db_name(DRS.database_id) [DBName],
DRS.last_commit_time
FROM sys.dm_hadr_database_replica_states DRS
INNER JOIN sys.availability_replicas AR ON DRS.replica_id = AR.replica_id
INNER JOIN sys.dm_hadr_availability_replica_states HARS ON AR.group_id = HARS.group_id
AND AR.replica_id = HARS.replica_id
),
Pri_CommitTime AS
(
SELECT replica_server_name
, DBName
, last_commit_time
FROM AG_Stats
WHERE role_desc = 'PRIMARY'
),
Sec_CommitTime AS
(
SELECT replica_server_name
, DBName
, last_commit_time
FROM AG_Stats
WHERE role_desc = 'SECONDARY'
),
Results AS
(
SELECT
AvailabilityGroupName,
DatabaseName,
[LAB-SCB-SQL01],
[LAB-SCB-SQL02],
[LAB-LAS-SQL01],
[LAB-LAS-SQL02],
[Max_Sync_Lag_Secs]
FROM(
SELECT
bb.AvailabilityGroupName,
bb.DatabaseName,
bb.NodeName,
bb.synchronization_health_desc,
MAX( DATEDIFF(ss,s.last_commit_time,p.last_commit_time)) OVER ( PARTITION BY NULL ) AS [Max_Sync_Lag_Secs]
FROM
basicaginfo bb
LEFT JOIN
Pri_CommitTime p ON p.DBName=bb.DatabaseName
LEFT JOIN
Sec_CommitTime s ON bb.NodeName = s.replica_server_name
) AS Data
PIVOT(
MAX( synchronization_health_desc ) FOR [NodeName] IN( [LAB-SCB-SQL01], [LAB-SCB-SQL02], [LAB-LAS-SQL01], [LAB-LAS-SQL02] )
) AS PivotedData
)
EXEC(@sql)【问题讨论】：
【参考方案1】：你不能这样做，cte 表只能被下一个 SQL 命令访问。
当您在内部执行命令 EXEC(@sql) 时，SQL 会执行多个命令。
尝试将所有代码移动到一个变量中。
DECLARE @sql NVARCHAR(MAX)
SET @sql=N'WITH basicaginfo AS(
SELECT
ag.name AS AvailabilityGroupName,
cs.replica_server_name AS NodeName,
rs.role_desc,
rs.synchronization_health_desc,
DB_NAME(drs.database_id) AS DatabaseName
FROM
sys.availability_groups ag
JOIN
sys.dm_hadr_availability_replica_cluster_states cs on ag.group_id = cs.group_id
JOIN
sys.dm_hadr_availability_replica_states rs ON (ag.group_id=rs.group_id AND cs.replica_id = rs.replica_id)
JOIN
sys.dm_hadr_database_replica_states drs ON (ag.group_id=drs.group_id AND cs.replica_id = drs.replica_id)
),
AG_Stats AS
(
SELECT AR.replica_server_name,
HARS.role_desc,
Db_name(DRS.database_id) [DBName],
DRS.last_commit_time
FROM sys.dm_hadr_database_replica_states DRS
INNER JOIN sys.availability_replicas AR ON DRS.replica_id = AR.replica_id
INNER JOIN sys.dm_hadr_availability_replica_states HARS ON AR.group_id = HARS.group_id
AND AR.replica_id = HARS.replica_id
),
Pri_CommitTime AS
(
SELECT replica_server_name
, DBName
, last_commit_time
FROM AG_Stats
WHERE role_desc = ''PRIMARY''
),
Sec_CommitTime AS
(
SELECT replica_server_name
, DBName
, last_commit_time
FROM AG_Stats
WHERE role_desc = ''SECONDARY''
),
Results AS
(
SELECT
AvailabilityGroupName,
DatabaseName,
[LAB-SCB-SQL01],
[LAB-SCB-SQL02],
[LAB-LAS-SQL01],
[LAB-LAS-SQL02],
[Max_Sync_Lag_Secs]
FROM(
SELECT
bb.AvailabilityGroupName,
bb.DatabaseName,
bb.NodeName,
bb.synchronization_health_desc,
MAX( DATEDIFF(ss,s.last_commit_time,p.last_commit_time)) OVER ( PARTITION BY NULL ) AS [Max_Sync_Lag_Secs]
FROM
basicaginfo bb
LEFT JOIN
Pri_CommitTime p ON p.DBName=bb.DatabaseName
LEFT JOIN
Sec_CommitTime s ON bb.NodeName = s.replica_server_name
) AS Data
PIVOT(
MAX( synchronization_health_desc ) FOR [NodeName] IN( [LAB-SCB-SQL01], [LAB-SCB-SQL02], [LAB-LAS-SQL01], [LAB-LAS-SQL02] )
) AS PivotedData
)
SELECT * FROM Results WHERE AvailabilityGroupName = ''LAB-VIP-USADB'' AND DatabaseName = ''CPS'''
EXEC(@sql)
我尝试在我的环境中运行此命令，但我收到以下错误，因为我没有表格。
Msg 208, Level 16, State 1, Line 1
Invalid object name 'sys.availability_groups'.
【讨论】：
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