UPDATE statement in SQLite modifies existing records in a table. Using SET, we can change a specific column while keeping other columns unchanged, and WHERE helps target particular rows.

Syntax

UPDATE table_name
SET column_name = value
WHERE condition;

Explanation:

• UPDATE specifies the table whose data needs modification.
• SET assigns a new value to the selected column.
• WHERE specifies which rows should be updated.
• Without WHERE, the specified column is updated in every row.

Updating Specific Column

Following program creates a STUDENTS table, inserts sample records, updates one student's name, and changes the address of students who satisfy a condition.

import sqlite3

connection = sqlite3.connect(":memory:")

try:
    connection.execute("""
        CREATE TABLE STUDENTS (
            SID INTEGER PRIMARY KEY,
            SNAME TEXT NOT NULL,
            SAGE INTEGER NOT NULL,
            ADDRESS TEXT
        )
    """)
    connection.executemany(
        """
        INSERT INTO STUDENTS (SID, SNAME, SAGE, ADDRESS)
        VALUES (?, ?, ?, ?)
        """,
        [
            (1, "Mohan", 22, "Ponnur"),
            (2, "Sudheer", 28, "Chebrolu"),
            (3, "Neha", 22, "Tenali"),
        ],
    )

    connection.commit()


    print("Original Table:")
    for row in connection.execute(
        "SELECT * FROM STUDENTS ORDER BY SID"
    ):
        print(row)


    connection.execute(
        "UPDATE STUDENTS SET SNAME = ? WHERE SID = ?",
        ("Sravan", 1),
    )


    connection.execute(
        "UPDATE STUDENTS SET ADDRESS = ? WHERE SAGE = ?",
        ("Naga", 22),
    )


    connection.commit()


    print("\nUpdated Table:")
    for row in connection.execute(
        "SELECT * FROM STUDENTS ORDER BY SID"
    ):
        print(row)

finally:
    connection.close()

Output

Explanation:

• sqlite3.connect(":memory:") creates an in-memory database for this example.
• CREATE TABLE defines four columns: SID, SNAME, SAGE, and ADDRESS.
• executemany() inserts three sample records using parameter placeholders.
• First UPDATE changes SNAME only for the row where SID equals 1.
• Second UPDATE changes ADDRESS for every row where SAGE equals 22.
• Question-mark placeholders pass values separately from the SQL statements, helping prevent SQL injection.
• commit() saves the changes, while SELECT retrieves the modified records.
• Finally block closes the database connection.