[英]Python insert to MySQL : Failed to record Price 1452 (23000): Cannot add or update a child row: a foreign key constraint fails
[英]ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails That I can't fix
我收到此错误:
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint
fails (\`GTFS\`.\`#sql-37d_16\`, CONSTRAINT \`#sql-37d_16_ibfk_1\` FOREIGN KEY
(\`service_id\`) REFERENCES \`calendar\` (\`service_id\`))
我正在尝试使用python创建数据库表,这是我尝试过的:
mycursor.execute("CREATE TABLE IF NOT EXISTS routes(route_id varchar(3) PRIMARY KEY, agency_id varchar(2) ,route_short_name varchar(20) ,route_long_name varchar(50) ,route_desc varchar(30) ,route_type varchar(30) ,route_url varchar(30) ,route_color varchar(30) ,route_text_color varchar(30)) ")
mycursor.execute("CREATE TABLE IF NOT EXISTS calendar (service_id varchar(4) PRIMARY KEY,monday varchar(4) ,tuesday varchar(4) ,wednesday varchar(4) ,thursday varchar(4) ,friday varchar(4) ,saturday varchar(4) ,sunday varchar(4) ,start_date varchar(8) ,end_date varchar(8)) ")
mycursor.execute("CREATE TABLE IF NOT EXISTS trips (route_id varchar(3) ,service_id varchar(4) ,trip_id varchar(6) PRIMARY KEY,trip_headsign varchar(20) ,trip_short_name varchar(3) ,direction_id varchar(1) ,block_id varchar(1) ,shape_id varchar(5) )")
mycursor.execute("ALTER TABLE trips ADD FOREIGN KEY (service_id) REFERENCES calendar(service_id); ")
mycursor.execute("ALTER TABLE trips ADD FOREIGN KEY (route_id) REFERENCES routes(route_id); ")
我期望将列表中提供的一些数据插入表中,但是我总是在终端中收到此错误
因为trips.service_id
列的某些值在公共列service_id
的父表( calendar
)表中不存在。
您可以尝试通过这样的插入语句插入这些值:
insert into calendar(...,service_id,...)
select ...,service_id,...
from trips t
where not exists ( select 0 from calendar where service_id=t.service_id );
在添加约束之前
ALTER TABLE trips ADD FOREIGN KEY (service_id) REFERENCES calendar(service_id);
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