检查在 PostgreSQL (node.js) 中检索了多少行

Question

我想知道如何在 node.js 中检查 PostgreSQL 中查询的行数我有这段代码。

    var client = new pg.Client(conString);
    client.connect();
    var query = client.query("SELECT * FROM users"); 
    query.on('row', function(row) {
      console.log(row);
    }); 

Answer 1

var client = new pg.Client(conString);

client.connect();

client.query("SELECT * FROM users", function(err, result) {
    console.log("Row count: %d",result.rows.length);  // n
});

Answer 2

另一种选择是使用该rowCount财产！像这样：

var pg = require('pg');

var pgClient = new pg.Client();
pgClient.connect();

var pgQuery = pgClient.query("SELECT * FROM information_schema.tables;");
pgQuery.on('error', function(err) {
    pgClient.end();
    console.error(err);
});
pgQuery.on('end', function(result) {
    pgClient.end();
    console.log(result.rowCount);
});

或者像这样：

var pg = require('pg');

var pgClient = new pg.Client();
pgClient.connect();

var pgQuery = pgClient.query("SELECT * FROM information_schema.tables;", function(err, result) {
    pgClient.end();
    if (err) return console.error(err);
    console.log(result.rowCount);
});