优化这段sql：WITH user_worker AS (SELECT Title, ID FROM [biUser]) SELECT user_worker.Title AS worker, COUNT(CASE WHEN (CASE WHEN bl.Checker = 0 THEN '' WHEN bl.Checker > 0 AND bl.Audited = -1 THEN 'NG' WHEN bl.Checker > 0 AND bl.Audited = 1 THEN 'OK' END) ='' THEN 1 END) as nullstr, COUNT(CASE WHEN (CASE WHEN bl.Checker = 0 THEN '' WHEN bl.Checker > 0 AND bl.Audited = -1 THEN 'NG' WHEN bl.Checker > 0 AND bl.Audited = 1 THEN 'OK' END) = 'OK' THEN 1 END) as okstr, COUNT(CASE WHEN (CASE WHEN bl.Checker = 0 THEN '' WHEN bl.Checker > 0 AND bl.Audited = -1 THEN 'NG' WHEN bl.Checker > 0 AND bl.Audited = 1 THEN 'OK' END) = 'NG' THEN 1 END) as NGstr, (COUNT(CASE WHEN (CASE WHEN bl.Checker = 0 THEN '' WHEN bl.Checker > 0 AND bl.Audited = -1 THEN 'NG' WHEN bl.Checker > 0 AND bl.Audited = 1 THEN 'OK' END) = 'OK' THEN 1 END) +COUNT(CASE WHEN (CASE WHEN bl.Checker = 0 THEN '' WHEN bl.Checker > 0 AND bl.Audited = -1 THEN 'NG' WHEN bl.Checker > 0 AND bl.Audited = 1 THEN 'OK' END) ='' THEN 1 END) )as totalOKStr FROM [bdWorkOrderList] bl LEFT JOIN [bdWorkOrder] bd ON bl.OrderID = bd.ID LEFT JOIN [reportMJWXJL] rwx ON bl.OrderID = rwx.OrderID LEFT JOIN [reportMJQHLHJL] rqh ON bl.OrderID = rqh.OrderID LEFT JOIN user_worker ON user_worker.ID = bl.Worker WHERE bd.IsDeleted = 0 AND bl.StepName LIKE 'Maker%' AND bl.StepName IN ('Maker修模', 'maker切换料号', 'Maker模具保养') AND DATEPART(MONTH, bl.StartTime) = DATEPART(MONTH, GETDATE()) and DATEPART(YEAR, bl.StartTime) = DATEPART(YEAR, GETDATE()) GROUP BY user_worker.Title

你可以尝试优化以上SQL查询的性能：

WITH user_worker AS (
    SELECT Title, ID
    FROM [biUser]
),
Counts AS (
    SELECT 
        bl.Worker,
        COUNT(CASE WHEN bl.Audited = -1 THEN 1 END) AS NGstr,
        COUNT(CASE WHEN bl.Audited = 1 THEN 1 END) AS okstr,
        COUNT(CASE WHEN bl.Audited IS NULL THEN 1 END) AS nullstr
    FROM [bdWorkOrderList] bl 
    LEFT JOIN [bdWorkOrder] bd ON bl.OrderID = bd.ID 
    LEFT JOIN [reportMJWXJL] rwx ON bl.OrderID = rwx.OrderID 
    LEFT JOIN [reportMJQHLHJL] rqh ON bl.OrderID = rqh.OrderID 
    LEFT JOIN user_worker ON user_worker.ID = bl.Worker
    WHERE bd.IsDeleted = 0 
        AND bl.StepName LIKE 'Maker%' 
        AND bl.StepName IN ('Maker修模', 'maker切换料号', 'Maker模具保养')
        AND DATEPART(MONTH, bl.StartTime) = DATEPART(MONTH, GETDATE())
        AND DATEPART(YEAR, bl.StartTime) = DATEPART(YEAR, GETDATE())
    GROUP BY bl.Worker
)
SELECT 
    uw.Title AS worker,
    c.nullstr,
    c.okstr,
    c.NGstr,
    (c.okstr + c.nullstr) AS totalOKStr
FROM Counts c
JOIN user_worker uw ON uw.ID = c.Worker;

在上述优化中，我使用了两个公共表表达式（CTE）：`user_worker` 和 `Counts`。首先，从 `[biUser]` 表中获取工人的标题和ID，存储在 `user_worker` CTE 中。然后，使用 `Counts` CTE 计算每个工人的统计数据，避免了重复计算。最后，通过将 `Counts` CTE 与 `user_worker` CTE 进行连接，选择所需的列并进行汇总。

请注意，在优化查询性能方面，你可能还需要考虑适当的索引来支持连接和过滤操作。具体索引的创建需要根据表结构和查询需求进行评估和调整。