Project Url: xizzhu/ask
Introduction: Android SQLite Kotlin Extensions
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Build Status Coverage Status API GitHub license JitPack

Kotlin extensions to simplify working with SQLite database.


  • Gradle: Add the following to your build.gradle: ```gradle repositories { maven { url "" } }

dependencies { implementation 'com.github.xizzhu:ask:$latest_version' }

### Create and Drop Tables
* To create a table, use the `createTable()` function:
database.createTable("tableName") {
  it["textColumn"] = TEXT + PRIMARY_KEY
  it["integerColumn"] = INTEGER + UNIQUE(ConflictClause.REPLACE)
  it["anotherTextColumn"] = TEXT + FOREIGN_KEY("referenceTable", "referenceColumn")

Each column must have one of the four types: BLOB, INTEGER, REAL, and TEXT. It can also also have one or more modifiers: PRIMARY_KEY, NOT_NULL, UNIQUE, DEFAULT, and FOREIGN_KEY.

More info can be found here.

  • To delete a table, use the dropTable() function:

  • To check if a table exists, use the hasTable() function:


Create and Drop Indices

  • To create an index, use the createIndex() function:

    database.createIndex("indexName", "tableName", "column1", "column2")
  • To delete an index, use the dropIndex() function:


Insert Values

To insert a row into a table, use the insert() function:

database.insert("tableName") {
  it["textColumn"] = "random text"
  it["integerColumn"] = 8964L

Update Values

To update an existing row, use the update() function:

database.update("tableName", { it["textColumn"] = "random new value" }) {
  ("integerColumn" eq 1L) and ("anotherTextColumn" eq "value")

It supports simple conditions like eq, less, etc., and logical conditions like and, or, etc. The full list of supported conditions can be found here.

Delete Values

  • To delete all values from a table, use the deleteAll() function:

  • To delete values matching certain conditions, use the delete() function:

    database.delete("tableName") {
    "integerColumn" eq 1L

    It supports same conditions as discussed in the Update Values section.

Query Values

To query values from a table, use the select() function:

val query ="tableName") {
  "integerColumn" eq 1L

It supports same conditions as discussed in the Update Values section.

The returned Query object can be further custmized by calling the groupBy(), limit() or other functions, e.g.:

  .having { max("integerColumn") greater 1L }

Note that the query is not executed, until asCursor() or one of the extension functions is called, e.g.:

// return a list of Pair<Integer, String>
query.toList { row ->
  row.getInt("integerColumn") to row.getString("textColumn")

// return the Integer value of integerColumn in the first row
query.first { row ->

More about Query can be found here.

Run a Transaction

  • To run a transaction, use the transaction() function:

    database.transaction {
    // your transaction code

    To abort the transaction, simply throw TransactionAbortedException.

  • To run a transaction with a return value, use the withTransaction() function:

    val value = database.withTransaction {
    // your transaction code that returns a value


Copyright (C) 2020 Xizhi Zhu

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.
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