INNER JOIN `year` ON `year`.year_id = class.class_year

这是一个 SQL 查询语句，用于在 class 表和 year 表之间执行内连接操作。它的作用是将两个表中 year_id 列相等的行连接起来，并返回匹配的行。具体来说，INNER JOIN 表示只返回两个表中都存在的行，`year` 和 class 是表名，class_year 是 class 表中的一个列，year_id 是 year 表中的一个列，所以这个查询语句的意思是将 class 表中的 class_year 列和 year 表中的 year_id 列进行匹配，然后返回匹配的行。

相关问题

优化sql：SELECT we.organization_id ,we.wip_entity_id ,case when wl.line_id is null then we.wip_entity_name else '' end wip_entity_name ,we.primary_item_id ,mtt.transaction_type_name ,mmt.transaction_date ,bd.department_code ,mmt.inventory_item_id ,mmt.subinventory_code ,mta.reference_account ,br.resource_code ,lu2.meaning as line_type_name ,mta.base_transaction_value ,mta.cost_element_id ,flv.meaning as cost_element ,wdj.class_code job_type_code ,ml.meaning job_type_name FROM (select * from gerp.mtl_material_transactions where substr(transaction_date,1,7) >= '2023-06' and transaction_source_type_id = 5) mmt inner join gerp.wip_entities we on mmt.organization_id = we.organization_id inner join gerp.mtl_transaction_accounts mta on mta.transaction_source_id = we.wip_entity_id and mta.transaction_id = mmt.transaction_id and mta.transaction_source_type_id = 5 inner join gerp.mtl_transaction_types mtt on mtt.transaction_type_id = mmt.transaction_type_id inner join mfg_lookups lu2 on lu2.lookup_code = mta.accounting_line_type and lu2.lookup_type = 'CST_ACCOUNTING_LINE_TYPE' inner join gerp.mtl_system_items_b msi on msi.inventory_item_id = mmt.inventory_item_id and msi.organization_id = mta.organization_id left join gerp.bom_departments bd on bd.department_id = mmt.department_id left join gerp.bom_resources br on br.resource_id = mta.resource_id left join gerp.wip_lines wl on wl.line_id = mmt.repetitive_line_id left join gerp.wip_discrete_jobs wdj on wdj.wip_entity_id = mta.transaction_source_id left join gerp.fnd_lookup_values_vl flv on cast(mta.cost_element_id as string) = flv.lookup_code and flv.lookup_type = 'CST_COST_CODE_TYPE' left join mfg_lookups ml on ml.lookup_code = wdj.job_type and ml.lookup_type = 'WIP_DISCRETE_JOB' 。其中mmt,we,mta,msi,wdj数据量很大

针对这个SQL语句，可以优化的地方有：

1. 使用JOIN语句时，可以根据数据量大小，将数据量大的表放在后面，这样可以避免在连接时出现性能问题。

2. 使用子查询时，可以在子查询中添加条件筛选，减少返回的数据量。

3. 可以对查询中的日期条件进行优化，例如使用日期范围查询时，可以使用BETWEEN关键字代替大于等于和小于等于的运算符。

4. 可以对大表进行分区或分片，以加快查询速度。

5. 可以对JOIN语句中的字段添加索引，以提高查询效率。

下面是对原SQL语句的优化：

SELECT 
    we.organization_id, 
    we.wip_entity_id, 
    CASE WHEN wl.line_id is null THEN we.wip_entity_name ELSE '' END wip_entity_name,
    we.primary_item_id, 
    mtt.transaction_type_name, 
    mmt.transaction_date, 
    bd.department_code, 
    mmt.inventory_item_id, 
    mmt.subinventory_code, 
    mta.reference_account, 
    br.resource_code, 
    lu2.meaning as line_type_name,
    mta.base_transaction_value, 
    mta.cost_element_id, 
    flv.meaning as cost_element, 
    wdj.class_code job_type_code, 
    ml.meaning job_type_name 
FROM 
    gerp.wip_entities we 
    INNER JOIN (
        SELECT 
            * 
        FROM 
            gerp.mtl_material_transactions 
        WHERE 
            transaction_date BETWEEN '2023-06-01' AND '2023-06-30' 
            AND transaction_source_type_id = 5
    ) mmt ON mmt.organization_id = we.organization_id 
    INNER JOIN gerp.mtl_transaction_accounts mta ON mta.transaction_source_id = we.wip_entity_id 
        AND mta.transaction_id = mmt.transaction_id 
        AND mta.transaction_source_type_id = 5 
    INNER JOIN gerp.mtl_transaction_types mtt ON mtt.transaction_type_id = mmt.transaction_type_id 
    INNER JOIN mfg_lookups lu2 ON lu2.lookup_code = mta.accounting_line_type AND lu2.lookup_type = 'CST_ACCOUNTING_LINE_TYPE' 
    INNER JOIN gerp.mtl_system_items_b msi ON msi.inventory_item_id = mmt.inventory_item_id 
        AND msi.organization_id = mta.organization_id 
    LEFT JOIN gerp.bom_departments bd ON bd.department_id = mmt.department_id 
    LEFT JOIN gerp.bom_resources br ON br.resource_id = mta.resource_id 
    LEFT JOIN gerp.wip_lines wl ON wl.line_id = mmt.repetitive_line_id 
    LEFT JOIN gerp.wip_discrete_jobs wdj ON wdj.wip_entity_id = mta.transaction_source_id 
    LEFT JOIN gerp.fnd_lookup_values_vl flv ON cast(mta.cost_element_id as string) = flv.lookup_code 
        AND flv.lookup_type = 'CST_COST_CODE_TYPE' 
    LEFT JOIN mfg_lookups ml ON ml.lookup_code = wdj.job_type AND ml.lookup_type = 'WIP_DISCRETE_JOB';

在优化后的SQL语句中，将子查询中的日期范围查询放在了WHERE语句中，将数据量较大的表放在了后面，左连接的表也放在了后面。同时，可以根据具体情况对需要添加索引的字段进行索引优化。

以hive的角度检查语法： with cur_dim_comb as (SELECT DISTINCT t.dim_comb ,t.var_sub_class ,t.acc_value FROM gerp.cux_cst_data_alloc_his t WHERE t.top_var_type = '10' AND t.job_ver_id in (SELECT ver.job_ver_id AS p_job_ver_id FROM gerp.cux_cst_dist_jobs_all job INNER JOIN gerp.cux_cst_dist_jobs_vers_all ver ON job.job_id = ver.job_id )) select tp.bd_code --事业部编码 ,tp.bd_name --事业部名称 ,hp.ou_code --OU名称 ,hp.ou_name --OU编码 ,op.main_class_desc --差异大类 ,op.acc_value --科目代码 ,op.acc_desc --科目名称 ,op.dim_comb --区分维度 ,op.begin_amount --期初余额 ,op.accrual_amount --本期发生 ,op.balance_diff_alloc_amount --期末差异结存 ,op.var_sub_class ,op.main_class_value ,op.org_id ,op.period_name ,op.job_ver_id from (select up.* ,q1.* from (SELECT DISTINCT maincl.* ,t.* FROM t inner join (SELECT fv.flex_value ,fv.description FROM fv inner join fs on fv.flex_value_set_id = fs.flex_value_set_id AND fs.flex_value_set_name = 'CUX_CST_VARIANCE_TYPE' AND fv.enabled_flag = 'Y' AND fv.hierarchy_level = '2' AND fv.flex_value LIKE '10%' ) maincl on t.var_main_class = maincl.flex_value inner join cur_dim_comb on cur_dim_comb.var_sub_class = t.var_sub_class and cur_dim_comb.acc_value = t.acc_value WHERE 1 = 1 AND t.top_var_type = '10' AND t.job_ver_id in (SELECT ver.job_ver_id AS p_job_ver_id FROM gerp.cux_cst_dist_jobs_all job INNER JOIN gerp.cux_cst_dist_jobs_vers_all ver ON job.job_id = ver.job_id) ORDER BY maincl.description ,t.acc_value ,cur_dim_comb.dim_comb ) up inner join (SELECT t1.* ,SUM(t1.begin_amount) begin_amount ,SUM(t1.accrual_amount) accrual_amount ,SUM(t1.balance_diff_alloc_amount) balance_diff_alloc_amount FROM gerp.cux_cst_data_alloc_his t1 LEFT JOIN gerp.cux_cst_data_alloc_his t ON t1.top_var_type = '10' AND t1.var_sub_class = t.var_sub_class --p_var_sub_class AND t1.org_id = t.org_id --p_org_id AND t1.period_name = t.period_name --p_period_name AND t1.job_ver_id = t.job_ver_id --p_job_ver_id AND t1.acc_value = t.acc_value --p_acc_value WHERE t1.dim_comb in (select distinct dim_comb from cur_dim_comb) group by t1.org_id,t1.period_name,t1.job_ver_id,t1.var_sub_class,t1.acc_value ) q1 on q1.org_id = up.org_id --p_org_id AND q1.period_name = up.period_name --p_period_name AND q1.job_ver_id = up.job_ver_id --p_job_ver_id AND q1.var_sub_class = up.var_sub_class --p_var_sub_class AND q1.acc_value = up.acc_value --p_acc_value ) op

从 Hive 的角度来检查语法，以下是您提供的 SQL 查询语句：

with cur_dim_comb as (
    SELECT DISTINCT t.dim_comb, t.var_sub_class, t.acc_value
    FROM gerp.cux_cst_data_alloc_his t
    WHERE t.top_var_type = '10'
    AND t.job_ver_id in (
        SELECT ver.job_ver_id AS p_job_ver_id
        FROM gerp.cux_cst_dist_jobs_all job
        INNER JOIN gerp.cux_cst_dist_jobs_vers_all ver
        ON job.job_id = ver.job_id
    )
)
select
    tp.bd_code, --事业部编码
    tp.bd_name, --事业部名称
    hp.ou_code, --OU名称
    hp.ou_name, --OU编码
    op.main_class_desc, --差异大类
    op.acc_value, --科目代码
    op.acc_desc, --科目名称
    op.dim_comb, --区分维度
    op.begin_amount, --期初余额
    op.accrual_amount, --本期发生
    op.balance_diff_alloc_amount, --期末差异结存
    op.var_sub_class,
    op.main_class_value,
    op.org_id,
    op.period_name,
    op.job_ver_id
from (
    select up.*, q1.*
    from (
        SELECT DISTINCT
            maincl.*,
            t.*
        FROM
            t
            inner join (
                SELECT
                    fv.flex_value,
                    fv.description
                FROM
                    fv
                    inner join fs
                    on fv.flex_value_set_id = fs.flex_value_set_id
                    AND fs.flex_value_set_name = 'CUX_CST_VARIANCE_TYPE'
                    AND fv.enabled_flag = 'Y'
                    AND fv.hierarchy_level = '2'
                    AND fv.flex_value LIKE '10%'
            ) maincl
            on t.var_main_class = maincl.flex_value
            inner join cur_dim_comb
            on cur_dim_comb.var_sub_class = t.var_sub_class
            and cur_dim_comb.acc_value = t.acc_value
        WHERE
            1 = 1
            AND t.top_var_type = '10'
            AND t.job_ver_id in (
                SELECT ver.job_ver_id AS p_job_ver_id
                FROM gerp.cux_cst_dist_jobs_all job
                INNER JOIN gerp.cux_cst_dist_jobs_vers_all ver
                ON job.job_id = ver.job_id
            )
        ORDER BY
            maincl.description,
            t.acc_value,
            cur_dim_comb.dim_comb
    ) up
    inner join (
        SELECT
            t1.*,
            SUM(t1.begin_amount) begin_amount,
            SUM(t1.accrual_amount) accrual_amount,
            SUM(t1.balance_diff_alloc_amount) balance_diff_alloc_amount
        FROM
            gerp.cux_cst_data_alloc_his t1
            LEFT JOIN gerp.cux_cst_data_alloc_his t
            ON t1.top_var_type = '10'
            AND t1.var_sub_class = t.var_sub_class --p_var_sub_class
            AND t1.org_id = t.org_id --p_org_id
            AND t1.period_name = t.period_name --p_period_name
            AND t1.job_ver_id = t.job_ver_id --p_job_ver_id
            AND t1.acc_value = t.acc_value --p_acc_value
        WHERE
            t1.dim_comb in (select distinct dim_comb from cur_dim_comb)
        group by
            t1.org_id,
            t1.period_name,
            t1.job_ver_id,
            t1.var_sub_class,
            t1.acc_value
    ) q1
    on q1.org_id = up.org_id --p_org_id
    AND q1.period_name = up.period_name --p_period_name
    AND q1.job_ver_id = up.job_ver_id --p_job_ver_id
    AND q1.var_sub_class = up.var_sub_class --p_var_sub_class
    AND q1.acc_value = up.acc_value --p_acc_value
) op

从语法角度来看，该查询语句是有效的。但是，如果您想要确保语句完全符合您的预期，请先测试该语句在您的环境中的执行结果。