为什么这个SQL代码会给出错误1066（不唯一的表/别名：'PROCESS''）？
这是我的桌面结构：
过程
pid process_type
1 test1
2 test2
3 test3
4 test4 >
子流程
subpro_id子流程process_id
1 subtest1 1
2 subtest2 1
3 subtest3 2
4 subtest4 2
inward_deviation
id frm_process frm_subprocess to_pocess to_subprocess
1 1 1 1 2
2 1 1 2 3
输出
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3
以下是我的代码。 />
This is my table structure:
process
pid process_type
1 test1
2 test2
3 test3
4 test4
subprocess
subpro_id subprocess process_id
1 subtest1 1
2 subtest2 1
3 subtest3 2
4 subtest4 2
inward_deviation
id frm_process frm_subprocess to_pocess to_subprocess
1 1 1 1 2
2 1 1 2 3
output
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3
The following is my code.
SELECT inward_deviation.user, inward_deviation.date, client.client_name, process.process_type as prot1, subprocess.sub_process, inward_deviation.remain_qty, inward_deviation.to_pocess as prot2
FROM process inner join(subprocess
INNER JOIN (
PROCESS INNER JOIN (
inward_deviation
INNER JOIN client ON inward_deviation.client_id = client.cid
) ON process.pid = inward_deviation.frm_process
) ON subprocess.subpro_id = inward_deviation.frm_subprocess) on process.pid=inward_deviation.to_pocess
SELECT inward_deviation.user，inward_deviation.date，client.client_name，process.process_type，subprocess.sub_process，inward_deviation.remain_qty，u2。 process_type，u3.sub_process
FROM subprocess u3
INNER JOIN（
PROCESS u2
INNER JOIN（
子流程
INNER JOIN（
流程内部联接（
inward_deviation
INNER JOIN客户端ON inta_deviation.client_id = client.cid
）ON process.pid = inward_deviation.frm_process
） ON subprocess.subpro_id = inward_deviation.frm_subprocess
）ON u2.pid = inward_deviation.to_pocess
）ON u3.subpro_id = inward_deviation.to_subprocess
输出
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3
查询成功...
SELECT inward_deviation.user, inward_deviation.date, client.client_name, process.process_type, subprocess.sub_process, inward_deviation.remain_qty, u2.process_type, u3.sub_process
FROM subprocess u3
INNER JOIN (
PROCESS u2
INNER JOIN (
subprocess
INNER JOIN (
PROCESS INNER JOIN (
inward_deviation
INNER JOIN client ON inward_deviation.client_id = client.cid
) ON process.pid = inward_deviation.frm_process
) ON subprocess.subpro_id = inward_deviation.frm_subprocess
) ON u2.pid = inward_deviation.to_pocess
) ON u3.subpro_id = inward_deviation.to_subprocess
output
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3
success the query...
SELECT inward_deviation.user，inward_deviation.date，client.client_name，process.process_type，subprocess.sub_process， inward_deviation.remain_qty，u2.process_type，u3.sub_process
FROM subprocess u3
INNER JOIN（
PROCESS u2
INNER JOIN（
子流程
INNER JOIN（
流程内部）加入（
inward_deviation
INNER JOIN客户端ON inta_deviation.client_id = client.cid
）ON process.pid = inward_deviation.frm_process
）ON subprocess.subpro_id = inward_deviation.frm_subprocess
）ON u2.pid = inward_deviation.to_pocess
）ON u3.subpro_id = inward_deviation.to_subprocess
输出
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3
SELECT inward_deviation.user, inward_deviation.date, client.client_name, process.process_type, subprocess.sub_process, inward_deviation.remain_qty, u2.process_type, u3.sub_process
FROM subprocess u3
INNER JOIN (
PROCESS u2
INNER JOIN (
subprocess
INNER JOIN (
PROCESS INNER JOIN (
inward_deviation
INNER JOIN client ON inward_deviation.client_id = client.cid
) ON process.pid = inward_deviation.frm_process
) ON subprocess.subpro_id = inward_deviation.frm_subprocess
) ON u2.pid = inward_deviation.to_pocess
) ON u3.subpro_id = inward_deviation.to_subprocess
output
id frm_process frm_subprocess to_pocess to_subprocess
1 test1 subtest1 test1 subtest1
2 test1 subtest1 test2 subtest3