Index Server

SQLDelight needs to know the schema of your database. There are typically two approaches to setting up your database's schema. The "Fresh Schema" approach assumes that you are starting with an empty database, and that all the statements necessary to bring it to the desired state will be applied all at once. The "Migration Schema" approach on the other hand assumes that you already have a database and schema set up (e.g. an existing production database), and that you'll progressively apply migrations over time to update your database's schema.

In SQLDelight, these approaches translate to either writing your table definitions in .sq files for a "Fresh Schema", or by writing migration statements in .sqm files for a "Migration Schema". In both cases, your SQL queries will be written in .sq files (as shown here).

Fresh Schema

{% include 'common/index_schema_sq.md' %}

In the same .sq files you can start placing your sql statements to be executed at runtime.

Migration Schema

First, configure gradle to use migrations to assemble the schema:

=== "Kotlin" kotlin sqldelight { databases { create("Database") { ... srcDirs("sqldelight") deriveSchemaFromMigrations.set(true) } } } === "Groovy" groovy sqldelight { databases { Database { ... srcDirs "sqldelight" deriveSchemaFromMigrations = true } } }

Migration files have the extension .sqm, and must have a number in their file name indicating what order the migration file runs in. For example, given this hierarchy:

src
`-- main
    `-- sqldelight
        |-- v1__backend.sqm
        `-- v2__backend.sqm

SQLDelight will create the schema by applying v1__backend.sqm and then v2__backend.sqm. Place your normal SQL CREATE/ALTER statements in these files. If another service reads from your migrations files (like flyway), make sure to read the info on migrations and how to output valid SQL.

Typesafe SQL

Before you're able to execute SQL statements at runtime, you need to create a SqlDriver to connect to your database. The easiest way is off of a DataSource that you would get from hikari or other connection managers.

=== "Kotlin" kotlin dependencies { implementation("app.cash.sqldelight:jdbc-driver:{{ versions.sqldelight }}") } === "Groovy" groovy dependencies { implementation "app.cash.sqldelight:jdbc-driver:{{ versions.sqldelight }}" }

val driver: SqlDriver = dataSource.asJdbcDriver()

Regardless of if you specify the schema as fresh create table statements or through migrations, runtime SQL goes in .sq files.

{% include 'common/index_queries.md' %}