stkvtflw stkvtflw - 6 months ago 266
SQL Question

How do I properly insert multiple rows into PG with node-postgres?

A single row can be inserted like this:

client.query("insert into tableName (name, email) values ($1, $2) ", ['john', 'john@gmail.com'], callBack)


This approach automatically comments out any special characters.

How do i insert multiple rows at once?

I need to implement this:

"insert into tableName (name, email) values ('john', 'john@gmail.com'), ('jane', 'jane@gmail.com')"


I can just use js string operators to compile such rows manually, but then i need to add special characters escape somehow.

Answer

Following this article: Performance Boost from pg-promise library, and its suggested approach:

// Concatenates an array of objects or arrays of values, according to the template,
// to use with insert queries. Can be used either as a class type or as a function.
//
// template = formatting template string
// data = array of either objects or arrays of values
function Inserts(template, data) {
    if (!(this instanceof Inserts)) {
        return new Inserts(template, data);
    }
    this._rawDBType = true;
    this.formatDBType = function () {
        return data.map(d=>'(' + pgp.as.format(template, d) + ')').join(',');
    };
}

An example of using it, exactly as in your case:

var users = [['John', 23], ['Mike', 30], ['David', 18]];

db.none('INSERT INTO Users(name, age) VALUES $1', Inserts('$1, $2', users))
    .then(data=> {
        // OK, all records have been inserted
    })
    .catch(error=> {
        // Error, no records inserted
    });

And it will work with an array of objects as well:

var users = [{name: 'John', age: 23}, {name: 'Mike', age: 30}, {name: 'David', age: 18}];

db.none('INSERT INTO Users(name, age) VALUES $1', Inserts('${name}, ${age}', users))
    .then(data=> {
        // OK, all records have been inserted
    })
    .catch(error=> {
        // Error, no records inserted
    });