Index.kt
/*
* Copyright (C) 2017 The Android Open Source Project
*
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.room.vo
import androidx.room.migration.bundle.BundleUtil
import androidx.room.migration.bundle.IndexBundle
/**
* Represents a processed index.
*/
data class Index(val name: String, val unique: Boolean, override val fields: Fields) :
HasSchemaIdentity, HasFields {
companion object {
// should match the value in TableInfo.Index.DEFAULT_PREFIX
const val DEFAULT_PREFIX = "index_"
}
constructor(name: String, unique: Boolean, fields: List<Field>) :
this(name, unique, Fields(fields))
override fun getIdKey() = "$unique-$name-${columnNames.joinToString(",")}"
fun createQuery(tableName: String): String {
val indexSQL = if (unique) {
"UNIQUE INDEX"
} else {
"INDEX"
}
return """
CREATE $indexSQL IF NOT EXISTS `$name`
ON `$tableName` (${columnNames.joinToString(", ") { "`$it`" }})
""".trimIndent().replace("\n", " ")
}
fun toBundle(): IndexBundle = IndexBundle(
name, unique, columnNames,
createQuery(BundleUtil.TABLE_NAME_PLACEHOLDER)
)
}