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Node.js - PostgreSQL - find rows where column is empty string (blank)
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In this article, we would like to show you how to find a row where the column is an empty stringΒ in the PostgreSQL database using Node.js.
Note:Β at the end of this article you can find database preparation SQL queries.
const { Client } = require('pg');
const client = new Client({
host: '127.0.0.1',
user: 'my_username',
database: 'my_database',
password: 'my_password',
port: 5432,
});
const findRows = async (text) => {
const query = `
SELECT *
FROM "users"
WHERE "email" = $1;
`;
await client.connect(); // creates connection
try {
const { rows } = await client.query(query, [text]); // sends query
return rows;
} finally {
await client.end(); // closes connection
}
};
findRows('') // empty string
.then(result => console.table(result))
.catch(error => console.error(error.stack));
Result:Β
βββββββββββ¬βββββ¬ββββββββββββββ¬ββββββββββββ¬ββββββββ
β (index) β id β name β surname β email β
βββββββββββΌβββββΌββββββββββββββΌββββββββββββΌββββββββ€
β 0 β 2 β 'Chris' β 'Brown' β '' β
β 1 β 3 β 'Kate' β 'Lewis' β '' β
β 2 β 5 β 'Gwendolyn' β 'James' β '' β
β 3 β 6 β 'Simon' β 'Collins' β '' β
β 4 β 7 β 'Taylor' β 'Martin' β '' β
βββββββββββ΄βββββ΄ββββββββββββββ΄ββββββββββββ΄ββββββββ
Database preparation
create_tables.sql
Β file:
CREATE TABLE "users" (
"id" SERIAL,
"name" VARCHAR(50) NOT NULL,
"surname" VARCHAR(50) NOT NULL,
"email" VARCHAR(50),
PRIMARY KEY ("id")
);
insert_data.sql
Β file:
INSERT INTO "users"
( "name", "surname", "email")
VALUES
('John', 'Stewart', 'john@email.com'),
('Chris', 'Brown', ''),
('Kate', 'Lewis',''),
('Ailisa', 'Gomez', 'ailisa@email.com'),
('Gwendolyn', 'James', ''),
('Simon', 'Collins', ''),
('Taylor', 'Martin',''),
('Andrew', 'Thompson', 'andrew123@email.com');
Native SQL query (used in the above example):
SELECT *
FROM "users"
WHERE "email" = $1;