Updating Data

In this section, we will discuss how to update data in a table using GlueSQL.

Basic Update

To update data in a table, you can use the update method on a table object, followed by the set method to specify the column and the new value. You can then use the execute method to apply the changes.

let actual = table("Foo")
    .update()
    .set("score", col("score").div(10))
    .execute(glue)
    .await;
let expected = Ok(Payload::Update(3));
test(actual, expected);

This code updates all rows in the table Foo, dividing the score column value by 10.

Update with Multiple Columns

To update multiple columns, you can chain multiple set methods with the desired column names and new values.

let actual = table("Foo")
    .update()
    .set("score", "score * 2 + 5")
    .set("flag", col("flag").negate())
    .execute(glue)
    .await;
let expected = Ok(Payload::Update(3));
test(actual, expected);

This code updates all rows in the table Foo, applying the following changes:

1. The score column value is multiplied by 2 and 5 is added.
2. The flag column value is negated (i.e., true becomes false and false becomes true).

Update with Filter

If you want to update only specific rows, you can use the filter method to provide a condition that the rows must meet.

let actual = table("Foo")
    .update()
    .set("score", "score * 2 + 5")
    .set("flag", col("flag").negate())
    .filter(col("score").lte(30))
    .execute(glue)
    .await;
let expected = Ok(Payload::Update(2));
test(actual, expected);

This code updates the rows in the table Foo where the score column value is less than or equal to 30. The score and flag column values are updated as described in the previous example.