Documentation for ExposedTable

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Iaroslav Postovalov 2021-05-09 15:19:07 +07:00
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@ -1,6 +1,5 @@
package space.kscience.dataforge.exposed
import org.jetbrains.exposed.dao.id.EntityID
import org.jetbrains.exposed.dao.id.IntIdTable
import org.jetbrains.exposed.sql.*
import org.jetbrains.exposed.sql.transactions.transaction
@ -12,26 +11,55 @@ import kotlin.reflect.KType
import kotlin.reflect.typeOf
import org.jetbrains.exposed.sql.Column as SqlColumn
/**
* Exposed based [Column] implementation.
*
* @param T The type of table items.
* @property db The Exposed database.
* @param sqlTable The Exposed table, which must follow the properties defined for [ExposedTable.sqlTable].
* @param sqlColumn The Exposed column.
* @param type The type of [T].
*/
public class ExposedColumn<T : Any>(
public val db: Database,
public val sqlTable: IntIdTable,
public val sqlColumn: SqlColumn<T>,
public override val type: KType,
) : Column<T> {
/**
* The name of this column.
*/
public override val name: String
get() = sqlColumn.name
/**
* Returns [Meta.EMPTY] because it is impossible to store metadata correctly with SQL columns.
*/
public override val meta: Meta
get() = Meta.EMPTY
/**
* Returns the count of rows in the table.
*/
public override val size: Int
get() = transaction(db) { sqlColumn.table.selectAll().count().toInt() }
/**
* Acquires the value of this column in the row [index].
*/
public override fun get(index: Int): T? = transaction(db) {
sqlTable.select { sqlTable.id eq index + 1 }.firstOrNull()?.getOrNull(sqlColumn)
}
}
/**
* Exposed based [Row] implementation.
*
* @param T The type of table items.
* @param db The Exposed database.
* @param sqlTable The Exposed table, which must follow the properties defined for [ExposedTable.sqlTable].
* @param sqlRow The Exposed row.
*/
@Suppress("UNCHECKED_CAST")
public class ExposedRow<T : Any>(
public val db: Database,
@ -39,19 +67,39 @@ public class ExposedRow<T : Any>(
public val sqlRow: ResultRow,
) :
Row<T> {
/**
* Acquires the value of [column] in this row.
*/
public override fun get(column: String): T? = transaction(db) {
val theColumn = sqlTable.columns.find { it.name == column } as SqlColumn<T>? ?: return@transaction null
sqlRow.getOrNull(theColumn)
}
}
/**
* Exposed based [Table] implementation.
*
* @property db The Exposed database.
*
* @property sqlTable The Exposed table. It must have the following properties:
* 1. Integer `id` column must be present with auto-increment by sequence 1, 2, 3&hellip;
* 1. All other columns must be of type [T].
*
* @property type The type of [T].
*/
@Suppress("UNCHECKED_CAST")
public class ExposedTable<T : Any>(public val db: Database, public val sqlTable: IntIdTable, public val type: KType) :
Table<T> {
public override val columns: List<Column<T>> =
/**
* The list of columns in this table.
*/
public override val columns: List<ExposedColumn<T>> =
sqlTable.columns.filterNot { it.name == "id" }.map { ExposedColumn(db, sqlTable, it as SqlColumn<T>, type) }
public override val rows: List<Row<T>>
/**
* The list of rows in this table.
*/
public override val rows: List<ExposedRow<T>>
get() = transaction(db) {
sqlTable.selectAll().map { ExposedRow(db, sqlTable, it) }
}
@ -64,9 +112,27 @@ public class ExposedTable<T : Any>(public val db: Database, public val sqlTable:
}
}
public inline fun <reified T : Any> ExposedTable(db: Database, table: IntIdTable): ExposedTable<T> =
ExposedTable(db, table, typeOf<T>())
/**
* Constructs [ExposedTable].
*
* @param T The type of table items.
* @param db The Exposed database.
* @param sqlTable The Exposed table, which must follow the properties defined for [ExposedTable.sqlTable].
* @return A new [ExposedTable].
*/
public inline fun <reified T : Any> ExposedTable(db: Database, sqlTable: IntIdTable): ExposedTable<T> =
ExposedTable(db, sqlTable, typeOf<T>())
/**
* Constructs [ExposedTable].
*
* @param T The type of table items.
* @param db The Exposed database.
* @param tableName The name of table.
* @param columns The list of columns' names.
* @param sqlColumnType The [IColumnType] for [T].
* @return A new [ExposedTable].
*/
public inline fun <reified T : Any> ExposedTable(
db: Database,
tableName: String,