0.0.0 • Published 9 years ago
pgschema-deletecascade v0.0.0
pgschema-deletecascade
uses a pgschematojson object to build a cascade delete batch query for any row.
yes i know postgresql has delete cascade. it might not be enabled for some reason. if you have this use case use this =)
the output sql string should be included in a transaction otherwise inconsistency problems will abound.
example
var del = require('pgschema-deletecascade')
var schema = require("./schema.json")
// now lets delete the row from the "main" table with primary key 1
var res = del(schema,"main",1)
// returns an array with the arguments that you would normally pass to pg query
// [query,arguments]
console.log(">query:")
process.stdout.write(res[0]+"\n")
console.log(">args")
console.log(res[1])
which outputs
>query:
delete from sub_sub where sub_id in (select id from sub where main_id in (?));
delete from sub where main_id in (?);
delete from main where id=?;
>args
[ 1, 1, 1 ]
in this case the schema.json looks like this
var schema = {
main:{
id:{
pkey:true,
dependents:[["sub","main_id"]]
}
},
sub:{
id:{
pkey:true,
dependents:[["sub_sub","sub_id"]]
},
main_id:{
fk:["main","id"]
}
},
sub_sub:{
sub_id:{
fk:["sub","id"]
}
}
}
api
module.exports(schema,tableName,primaryKeyValue)
- schema, is an object as produced from your db schema from the module pgschematojson
- tableName, the table you would like to delete from
- primaryKeyvalue, the id of the row you want to delete
0.0.0
9 years ago