如何将子表记录和主表记录在同一行显示

CREATE TABLE table1

(

id bigint NOT NULL,

name character varying(50),

CONSTRAINT table1_pkey PRIMARY KEY (id )

)

WITH (

OIDS=FALSE

);

CREATE TABLE tablesub1

(

dbid bigint NOT NULL,

reftableid bigint,

name character varying(50),

value character varying(50),

CONSTRAINT tablesub1_pkey PRIMARY KEY (dbid ),

CONSTRAINT tablesub1_reftableid_fkey FOREIGN KEY (reftableid)

REFERENCES table1 (id) MATCH SIMPLE

ON UPDATE NO ACTION ON DELETE NO ACTION

)

WITH (

OIDS=FALSE

);

table1

id name

1;"jack"

2;"jack1"

3;"jack2"

4;"jack3"

tablesub1

dbid refertableid name value

1;1;"p_task_name";"a"

2;1;"due_date";"b"

3;2;"p_task_name";"c"

4;2;"due_date";"d"

SELECT mainTable.id,mainTable.name, name3,value3, name4,value5

FROM (

SELECT id,name,name2 as name3 ,value as value3

FROM (

SELECT a1.*,a2.name as name2, a2.value as value

FROM table1 a1

LEFT JOIN tablesub1 a2 ON a1.id=a2.reftableid

) a

WHERE a.name2 = 'p_task_name'

) mainTable

LEFT JOIN (

SELECT id,name,name2 AS name4 ,value AS value5

FROM (

SELECT b1.*,b2.name AS name2, b2.value AS value

FROM table1 b1

LEFT JOIN tablesub1 b2 ON b1.id=b2.reftableid

) b

WHERE b.name2 = 'due_date'

) leftjoinTable

ON mainTable.id = leftjoinTable.id

结果

1;"jack";"p_task_name";"a";"due_date";"b"

2;"jack1";"p_task_name";"c";"due_date";"d"