Я пытаюсь выполнить список команд SQL последовательно с ниже кода. но я мог видеть, что последовательность не гарантируется из-под подхода. Каким будет правильный подход?
deletegrpquery = 'delete FROM grp where grp_id=(?)';
deleteuserassociations = 'delete FROM grp_usr where grp_id=(?)';
deleteexpensesofgrp = 'delete FROM exp where exp_grp=(?)';
deletepaidbyentries = 'delete FROM paidby where paid_exp in ( select exp_id from exp where exp_grp=(?))';
deleteapplicabletoentries = 'delete FROM applicableto where applicable_exp in ( select exp_id from exp where exp_grp=(?)';
deletesettlements = 'delete from settlements where settlement_grp=(?)';
cleanup_applicable = 'delete FROM applicableto where applicable_exp not in (select exp_id from exp)';
cleanup_paidby = 'delete FROM applicableto where applicable_exp not in (select exp_id from exp)';
querylistfordeletegrp = [deletepaidbyentries, deleteapplicabletoentries, deletesettlements, deleteuserassociations, deletegrpquery,deleteexpensesofgrp, cleanup_applicable, cleanup_paidby];
angular.forEach(querylistfordeletegrp, function(query) {
DB.query(query, [grp_id]).then(function(result) {
console.log(query);
});
})
var promise = $q.when();
angular.forEach(querylistfordeletegrp, function(query) {
promise = promise.then(function() {
return DB.query(query, [grp_id]);
});
});
$ q.serial помог добиться этого более чистым способом http://www.codeducky.org/q-serial/
deletegrpquery = 'delete FROM grp where grp_id=(?)';
deleteuserassociations = 'delete FROM grp_usr where grp_id=(?)';
deleteexpensesofgrp = 'delete FROM exp where exp_grp=(?)';
deletepaidbyentries = 'delete FROM paidby where paid_exp in ( select exp_id from exp where exp_grp=(?))';
deleteapplicabletoentries = 'delete FROM applicableto where applicable_exp in ( select exp_id from exp where exp_grp=(?))';
deletesettlements = 'delete from settlements where settlement_grp=(?)';
cleanup_applicable = 'delete FROM applicableto where applicable_exp not in (select exp_id from exp)';
cleanup_paidby = 'delete FROM paidby where paid_exp not in (select exp_id from exp)';
querylistfordeletegrp = [deletepaidbyentries, deleteapplicabletoentries, deletesettlements, deleteuserassociations, deletegrpquery, deleteexpensesofgrp, cleanup_applicable, cleanup_paidby];
// solution
var tasks = querylistfordeletegrp.map(function(query) {
return function() {
return DB.query(query, [grp_id]);
};
});
$q.serial(tasks);
Сделайте функцию executeNextQuery() и вызовите ее рекурсивно изнутри then()
then
обратном вызове. И так далее. Там могут быть библиотеки для облегчения этой вещи.