我正试图在mysql5.7中实现三个临时表的完全连接。我正在模拟这个例子（如何在mysql中实现完整的外部连接？），但是我找不到也不知道如何用三个表而不是两个表来实现这一点。
我写过：

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#### QUERY GOALS: Number of Members Gained to X trigger & Number of Members Lost from X trigger

# to do

## add in parameters for ladders

########################################################################################## 

#### DROP TABLE IF EXISTS

DROP TABLE IF EXISTS cte_leenk_ladder_history; 
DROP TABLE IF EXISTS cte_ladder_history_self_join_lh1;
DROP TABLE IF EXISTS cte_ladder_history_self_join_lh2;
DROP TABLE IF EXISTS cte_ladder_history_join_lh1_lh2_current_trigger_record;
DROP TABLE IF EXISTS cte_distinct_completed_trigger_and_moved;
DROP TABLE IF EXISTS cte_completed_trigger_prior_to_date_no_change; 
DROP TABLE IF EXISTS cte_completed_trigger_between_dates_no_change;
DROP TABLE IF EXISTS cte_completed_trigger_between_dates_then_change;    

# set @ladder_value = 'ladder_advocacy';

#### CREATE PARAMETERS FOR LADDERS

    CREATE TEMPORARY TABLE cte_leenk_ladder_history
        SELECT 
        member_id
        ,ladder_change
        ,date_trigger_event
        ,@ladder_value
        ,lh.ladder_config_id as ladder_config_id
        ,trigger_name
        ,coalesce(lh.ladder_advocacy,lh.ladder_elected,lh.ladder_policy,lh.ladder_organizing,lh.ladder_organizing,lh.ladder_engagement) as ladder_value 
        ,CASE WHEN lh.ladder_advocacy is not null THEN 'ladder_advocacy'
               WHEN lh.ladder_elected is not null THEN 'ladder_elected'
               WHEN lh.ladder_policy is not null THEN 'ladder_policy'
               WHEN lh.ladder_organizing is not null THEN 'ladder_organizing'
               WHEN lh.ladder_collective is not null THEN 'ladder_collective'
               WHEN lh.ladder_engagement is not null THEN 'ladder_engagement'
            END
            AS ladder_name
        FROM leeds_new.leenk_ladder_history as lh 
            inner join leeds_new.leenk_ladder_config as lc on lh.ladder_config_id = lc.ladder_config_id
            where lh.ladder_change = 1 and lc.active = 1 and lc.trigger = 1 
        limit 25000;

#### SET UP MASTER TABLE

create temporary table cte_ladder_history_self_join_lh1 
    select 
        member_id as member_id_lh1, 
        ladder_config_id as ladder_config_id_lh1, 
        trigger_name as trigger_name_lh1,
        date_trigger_event as date_trigger_event_lh1,
        ladder_name as ladder_name_lh1,
        ladder_value as ladder_value_lh1,
        ladder_change as ladder_change_lh1 

    from 
        cte_leenk_ladder_history as lh1; 

create temporary table cte_ladder_history_self_join_lh2 
    select 
        member_id as member_id_lh2, 
        trigger_name as trigger_name_lh2,
        date_trigger_event as date_trigger_event_lh2,
        ladder_name as ladder_name_lh2,
        ladder_value as ladder_value_lh2,
        ladder_change as ladder_change_lh2  

    from 
        cte_leenk_ladder_history as lh2; 

#### Current ladder history

create temporary table cte_ladder_history_join_lh1_lh2_current_trigger_record 
    select 
        cte_ladder_history_self_join_lh1.member_id_lh1,
        cte_ladder_history_self_join_lh1.ladder_config_id_lh1,
        cte_ladder_history_self_join_lh1.trigger_name_lh1,
        cte_ladder_history_self_join_lh1.date_trigger_event_lh1,
        cte_ladder_history_self_join_lh1.ladder_name_lh1,
        cte_ladder_history_self_join_lh1.ladder_value_lh1,
        cte_ladder_history_self_join_lh1.ladder_change_lh1,
        cte_ladder_history_self_join_lh2.member_id_lh2,
        cte_ladder_history_self_join_lh2.trigger_name_lh2,
        cte_ladder_history_self_join_lh2.date_trigger_event_lh2,
        cte_ladder_history_self_join_lh2.ladder_name_lh2,
        cte_ladder_history_self_join_lh2.ladder_value_lh2,
        cte_ladder_history_self_join_lh2.ladder_change_lh2,
        @member_id:=member_id_lh2 AS member_id,
        @row_number:=(CASE
                WHEN @member_id = member_id_lh1
                THEN @row_number + 1
                ELSE 1
            END) AS rank

    from 
        cte_ladder_history_self_join_lh1 #previous or current ladder history 
            left join cte_ladder_history_self_join_lh2 on cte_ladder_history_self_join_lh1.member_id_lh1 = cte_ladder_history_self_join_lh2.member_id_lh2
                and cte_ladder_history_self_join_lh2.ladder_name_lh2 = cte_ladder_history_self_join_lh1.ladder_name_lh1
                and cte_ladder_history_self_join_lh1.ladder_value_lh1 <> cte_ladder_history_self_join_lh2.ladder_value_lh2
                and cte_ladder_history_self_join_lh1.date_trigger_event_lh1 < cte_ladder_history_self_join_lh2.date_trigger_event_lh2 # lh2 shows second begin date / end date for lh if exists
        where @row_number:=(CASE
                WHEN @member_id = member_id_lh1
                THEN @row_number + 1
                ELSE 1
           END) = 1
        order by member_id_lh1 desc, date_trigger_event_lh2 desc; 

#### count people who completed X trigger level prior to date and havent changed ever

    create temporary table cte_completed_trigger_prior_to_date_no_change
        select 
            cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1 as trigger_name__prior_to_date_no_change, #try removing trigger name grouping for ladder level counts
            cte_ladder_history_join_lh1_lh2_current_trigger_record.ladder_value_lh1,
            count(cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1) as count_trigger_prior_no_change

        from cte_ladder_history_join_lh1_lh2_current_trigger_record
            where date_trigger_event_lh1 < CAST('2018-01-01' AS DATE)
            and member_id_lh2 is null
        group by trigger_name_lh1, ladder_value_lh1
        order by ladder_value_lh1 asc; 

#### count people who completed X trigger level between dates that never became something else

    create temporary table cte_completed_trigger_between_dates_no_change
        select 
            cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1 as trigger_name__between_dates_no_change,
            cte_ladder_history_join_lh1_lh2_current_trigger_record.ladder_value_lh1,
            count(cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1) as count_trigger_between_no_change

        from cte_ladder_history_join_lh1_lh2_current_trigger_record
            where date_trigger_event_lh1 BETWEEN CAST('2018-01-01' AS DATE) AND CAST('2018-12-01' AS DATE)
            and member_id_lh2 is null 
        group by trigger_name_lh1, ladder_value_lh1
        order by ladder_value_lh1 asc; 

#### count people who completed X trigger level between dates AND became something else (people who moved on)

    create temporary table cte_completed_trigger_between_dates_then_change
        select 
            cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1 as trigger_name__between_dates_change,
            cte_ladder_history_join_lh1_lh2_current_trigger_record.ladder_value_lh1,
            count(cte_ladder_history_join_lh1_lh2_current_trigger_record.trigger_name_lh1) as count_trigger_between_then_change

        from cte_ladder_history_join_lh1_lh2_current_trigger_record
            where date_trigger_event_lh1 BETWEEN CAST('2018-01-01' AS DATE) AND CAST('2018-12-01' AS DATE)
            and member_id_lh2 is not null 
        group by trigger_name_lh1, ladder_value_lh1
        order by ladder_value_lh1 asc; 

#### join the counts together - do this 3 times, for each table

/* t1 t2 */ 
        select * from cte_completed_trigger_prior_to_date_no_change
            left join cte_completed_trigger_between_dates_no_change on cte_completed_trigger_prior_to_date_no_change.trigger_name__prior_to_date_no_change = cte_completed_trigger_between_dates_no_change.trigger_name__between_dates_no_change
            union 
        select * from cte_completed_trigger_prior_to_date_no_change
            right join cte_completed_trigger_between_dates_no_change on cte_completed_trigger_prior_to_date_no_change.trigger_name__prior_to_date_no_change = cte_completed_trigger_between_dates_no_change.trigger_name__between_dates_no_change

/* t1 t3 */
        select * from cte_completed_trigger_prior_to_date_no_change
            left join cte_completed_trigger_between_dates_then_change on cte_completed_trigger_prior_to_date_no_change.trigger_name__prior_to_date_no_change = cte_completed_trigger_between_dates_then_change.trigger_name__between_dates_change
            union 
        select * from cte_completed_trigger_prior_to_date_no_change
            right join cte_completed_trigger_between_dates_then_change on cte_completed_trigger_prior_to_date_no_change.trigger_name__prior_to_date_no_change = cte_completed_trigger_between_dates_then_change.trigger_name__between_dates_change
/* t2 t3 */ 
        select * from cte_completed_trigger_between_dates_no_change
            left join cte_completed_trigger_between_dates_then_change on cte_completed_trigger_between_dates_no_change.trigger_name__between_dates_no_change = cte_completed_trigger_between_dates_then_change.trigger_name__between_dates_change
            union 
        select * from cte_completed_trigger_between_dates_no_change
            right join cte_completed_trigger_between_dates_then_change on cte_completed_trigger_between_dates_no_change.trigger_name__between_dates_no_change = cte_completed_trigger_between_dates_then_change.trigger_name__between_dates_change

所讨论的连接位于查询的末尾。我得到一个“语法错误”。我也尝试过这种方法（如何在mysql中完全外部连接多个表）和这种方法（我的）sql完全连接三个表）
思想？