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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 string in the PostgreSQL database using Node.js.
Note: at the end of this article you can find database preparation SQL queries.
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const { Client } = require('pg');2
3
const client = new Client({4
host: '127.0.0.1',5
user: 'my_username',6
database: 'my_database',7
password: 'my_password',8
port: 5432,9
});10
11
const findRows = async (text) => {12
const query = `13
SELECT * 14
FROM "users" 15
WHERE "email" = $1;16
`;17
await client.connect(); // creates connection18
try {19
const { rows } = await client.query(query, [text]); // sends query20
return rows;21
} finally {22
await client.end(); // closes connection23
}24
};25
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findRows('') // empty string 27
.then(result => console.table(result))28
.catch(error => console.error(error.stack));Result:
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┌─────────┬────┬─────────────┬───────────┬───────┐2
│ (index) │ id │ name │ surname │ email │3
├─────────┼────┼─────────────┼───────────┼───────┤4
│ 0 │ 2 │ 'Chris' │ 'Brown' │ '' │5
│ 1 │ 3 │ 'Kate' │ 'Lewis' │ '' │6
│ 2 │ 5 │ 'Gwendolyn' │ 'James' │ '' │7
│ 3 │ 6 │ 'Simon' │ 'Collins' │ '' │8
│ 4 │ 7 │ 'Taylor' │ 'Martin' │ '' │9
└─────────┴────┴─────────────┴───────────┴───────┘create_tables.sql file:
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CREATE TABLE "users" (2
"id" SERIAL,3
"name" VARCHAR(50) NOT NULL,4
"surname" VARCHAR(50) NOT NULL,5
"email" VARCHAR(50),6
PRIMARY KEY ("id")7
);insert_data.sql file:
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INSERT INTO "users"2
( "name", "surname", "email")3
VALUES4
('John', 'Stewart', 'john@email.com'),5
('Chris', 'Brown', ''),6
('Kate', 'Lewis',''),7
('Ailisa', 'Gomez', 'ailisa@email.com'),8
('Gwendolyn', 'James', ''),9
('Simon', 'Collins', ''),10
('Taylor', 'Martin',''),11
('Andrew', 'Thompson', 'andrew123@email.com');Native SQL query (used in the above example):
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SELECT * 2
FROM "users" 3
WHERE "email" = $1;