Database Service

The Database Service DSL is a wrapper for the Database Service module provided by CSW. You can refer to detailed documentation of the Database Service provided by CSW here.

This DSL provides APIs to create the connection to database. It uses Jooq library underneath for crating database connections and query.

Create Database Connection (Read Access)

This API allows creating connection to database with default read access. The username and password for read access is picked from environment variables set on individual’s machine i.e. DB_READ_USERNAME and DB_READ_PASSWORD. It is expected that developers set these variables before calling this method. It returns Jooq’s DSLContext or fails with DatabaseException. DSLContext provide methods like fetchAsync, executeAsync, executeBatch, etc. Moreover, see JooqHelper in CSW which provides wrapper methods on Jooq’s DSLContext. For methods returning Future, script will need to await for sequential flow.

Following example shows creating database connection and querying database.

Kotlin

val readDslContext = makeDatabaseService(dbName = "IRIS_db")

onSetup("setup-iris") {
    val query = readDslContext
            .resultQuery("SELECT filter_key FROM filter_table")

    //await to get result of query to achieve sequential flow of execution
    val filterKeys = JooqHelper.fetchAsync(query, String::class.java).await()

    // do something with filter keys
}

Create Database Connection (with provided access)

This API allows creating the connection to database with credentials picked from environment variables. Names of these environment variables is expected as method parameters and developers are expected to set these variables before calling this method. If user provides names for write credentials environment variables, then database connection will be created with write access. It returns Jooq’s DSLContext or fails with DatabaseException. DSLContext provide methods like fetchAsync, executeAsync, executeBatch, etc. Moreover, see JooqHelper in CSW which provides wrapper methods on Jooq’s DSLContext. For methods returning Future, script will need to await for sequential flow.

Following example shows creating database connection with write access.

Kotlin

val context = makeDatabaseService("IRIS_db", "db_write_username", "db_write_password")

Source code for examples

• Database Service Examples