Dialects
Overview
Dialects absorb differences in databases and drivers. A typical function of dialects is to resolve the type mappings between Kotlin and SQL.
The classes representing dialects are contained in separate modules (artifacts), and the choice of which module to use must be based on the destination database and connectivity type.
| Database | Type | Artifact ID | Dialect Class | Supported Database Version |
|---|---|---|---|---|
| H2 Database Engine | JDBC | komapper-dialect-h2-jdbc | H2JdbcSqlDialect | v2.2.222 and above |
| H2 Database Engine | R2DBC | komapper-dialect-h2-r2dbc | H2R2dbcSqlDialect | v2.2.222 and above |
| MariaDB | JDBC | komapper-dialect-mariadb-jdbc | MariaDbJdbcDialect | v10.6.3 and above |
| MariaDB | R2DBC | komapper-dialect-mariadb-r2dbc | MariaDbR2dbcDialect | v10.6.3 and above |
| MySQL | JDBC | komapper-dialect-mysql-jdbc | MySqlJdbcDialect | v5.7.x and v8.x |
| MySQL | R2DBC | komapper-dialect-mysql-r2dbc | MySqlR2dbcDialect | v5.7.x and v8.x |
| Oracle Database | JDBC | komapper-dialect-oracle-jdbc | OracleJdbcDialect | v18c and above |
| Oracle Database | R2DBC | komapper-dialect-oracle-r2dbc | OracleR2dbcDialect | v18c and above |
| PostgreSQL | JDBC | komapper-dialect-postgresql-jdbc | PostgreSqlJdbcDialect | v12.9 and above |
| PostgreSQL | R2DBC | komapper-dialect-postgresql-r2dbc | PostgreSqlR2dbcDialect | v12.9 and above |
| SQL Server | JDBC | komapper-dialect-sqlserver-jdbc | SqlServerJdbcDialect | v2019 and above |
| SQL Server | R2DBC | komapper-dialect-sqlserver-r2dbc | SqlServerR2dbcDialect | v2019 and above |
To use a dialect, specify the Artifact ID above in the Gradle dependencies declaration.
val komapperVersion: String by project
dependencies {
implementation("org.komapper:komapper-dialect-h2-jdbc:$komapperVersion")
}
H2 - JDBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | NUMERIC | |
| java.math.BigInteger | NUMERIC | |
| java.sql.Array | ARRAY | |
| java.sql.Blob | BLOB | |
| java.sql.Clob | CLOB | |
| java.sql.NClob | CLOB | |
| java.sql.SQLXML | CLOB | |
| java.time.Instant | TIMESTAMP WITH TIME ZONE | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | TIMESTAMP | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP WITH TIME ZONE | |
| java.util.UUID | UUID | |
| kotlin.Any | JAVA_OBJECT | |
| kotlin.Boolean | BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | BINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | REAL | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | CLOB | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP WITH TIME ZONE | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | TIMESTAMP | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
H2 - R2DBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.spi.Blob | BLOB | |
| io.r2dbc.spi.Clob | CLOB | |
| java.math.BigDecimal | NUMERIC | |
| java.math.BigInteger | NUMERIC | |
| java.time.Instant | TIMESTAMP WITH TIME ZONE | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | TIMESTAMP | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP WITH TIME ZONE | |
| java.util.UUID | UUID | |
| kotlin.Any | N/A | |
| kotlin.Boolean | BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | BINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | REAL | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | CLOB | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP WITH TIME ZONE | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | TIMESTAMP | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
MariaDB - JDBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | DECIMAL | |
| java.math.BigInteger | DECIMAL | |
| java.sql.Array | N/A | |
| java.sql.Blob | BLOB | |
| java.sql.Clob | TEXT | |
| java.sql.NClob | TEXT | |
| java.sql.SQLXML | TEXT | |
| java.time.Instant | TIMESTAMP | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | DATETIME | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | BIT(1), BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | VARBINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | FLOAT | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | TEXT | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | DATETIME | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
MariaDB - R2DBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.spi.Blob | BLOB | |
| io.r2dbc.spi.Clob | TEXT | |
| java.math.BigDecimal | DECIMAL | |
| java.math.BigInteger | DECIMAL | |
| java.time.Instant | TIMESTAMP | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | DATETIME | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | BIT(1), BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | VARBINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | FLOAT | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | TEXT | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | DATETIME | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
MySQL - JDBC
The MySQL Dialect in our system supports both MySQL versions 5 and 8, with the default being version 8. To instantiate a Dialect specifically for version 5, you should explicitly specify the version as follows:
val dialect = MySqlJdbcDialect(MySqlVersion.V5)
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | DECIMAL | |
| java.math.BigInteger | DECIMAL | |
| java.sql.Array | N/A | |
| java.sql.Blob | BLOB | |
| java.sql.Clob | TEXT | |
| java.sql.NClob | TEXT | |
| java.sql.SQLXML | TEXT | |
| java.time.Instant | TIMESTAMP | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | DATETIME | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | BIT(1), BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | VARBINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | FLOAT | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | TEXT | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | DATETIME | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
MySQL - R2DBC
The MySQL Dialect in our system supports both MySQL versions 5 and 8, with the default being version 8. To instantiate a Dialect specifically for version 5, you should explicitly specify the version as follows:
val dialect = MySqlR2dbcDialect(MySqlVersion.V5)
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.spi.Blob | N/A | |
| io.r2dbc.spi.Clob | N/A | |
| java.math.BigDecimal | DECIMAL | |
| java.math.BigInteger | DECIMAL | |
| java.time.Instant | TIMESTAMP | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | DATETIME | |
| java.time.LocalTime | N/A | |
| java.time.OffsetDateTime | TIMESTAMP | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | BIT(1), BOOLEAN | |
| kotlin.Byte | TINYINT | |
| kotlin.ByteArray | VARBINARY | |
| kotlin.Double | DOUBLE | |
| kotlin.Float | FLOAT | |
| kotlin.Int | INT | |
| kotlin.Long | BIGINT | |
| kotlin.Short | SMALLINT | |
| kotlin.String | VARCHAR | |
| kotlin.String | TEXT | ClobString must be specified as alternate type. |
| kotlin.UByte | SMALLINT | |
| kotlin.UInt | BIGINT | |
| kotlin.UShort | INT | |
| kotlinx.datetime.Instant | TIMESTAMP | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | DATETIME | |
| enum class | VARCHAR | Can be customized by @KomapperEnum or komapper.enumStrategy. |
Oracle - JDBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | NUMBER | |
| java.math.BigInteger | NUMBER | |
| java.sql.Array | N/A | |
| java.sql.Blob | BLOB | |
| java.sql.Clob | CLOB | |
| java.sql.NClob | N/A | |
| java.sql.SQLXML | N/A | |
| java.time.Instant | TIMESTAMP WITH TIME ZONE | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | TIMESTAMP | |
| java.time.LocalTime | TIME | |
| java.time.OffsetDateTime | TIMESTAMP WITH TIME ZONE | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | NUMBER | |
| kotlin.Byte | NUMBER | |
| kotlin.ByteArray | RAW | |
| kotlin.Double | FLOAT | |
| kotlin.Float | FLOAT | |
| kotlin.Int | NUMBER | |
| kotlin.Long | NUMBER | |
| kotlin.Short | NUMBER | |
| kotlin.String | VARCHAR2 | |
| kotlin.String | CLOB | ClobString must be specified as alternate type. |
| kotlin.UByte | NUMBER | |
| kotlin.UInt | NUMBER | |
| kotlin.UShort | NUMBER | |
| kotlinx.datetime.Instant | TIMESTAMP WITH TIME ZONE | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | TIMESTAMP | |
| enum class | VARCHAR2 | Can be customized by @KomapperEnum or komapper.enumStrategy. |
Oracle - R2DBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.spi.Blob | BLOB | |
| io.r2dbc.spi.Clob | CLOB | |
| java.math.BigDecimal | NUMBER | |
| java.math.BigInteger | NUMBER | |
| java.time.Duration | INTERVAL DAY TO SECOND | |
| java.time.Instant | TIMESTAMP WITH TIME ZONE | |
| java.time.LocalDate | DATE | |
| java.time.LocalDateTime | TIMESTAMP | |
| java.time.LocalTime | TIME | |
| java.time.Period | INTERVAL YEAR TO MONTH | |
| java.time.OffsetDateTime | TIMESTAMP WITH TIME ZONE | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | NUMBER | |
| kotlin.Byte | NUMBER | |
| kotlin.ByteArray | RAW | |
| kotlin.Double | FLOAT | |
| kotlin.Float | FLOAT | |
| kotlin.Int | NUMBER | |
| kotlin.Long | NUMBER | |
| kotlin.Short | NUMBER | |
| kotlin.String | VARCHAR2 | |
| kotlin.String | CLOB | ClobString must be specified as alternate type. |
| kotlin.UByte | NUMBER | |
| kotlin.UInt | NUMBER | |
| kotlin.UShort | NUMBER | |
| kotlinx.datetime.Instant | TIMESTAMP WITH TIME ZONE | |
| kotlinx.datetime.LocalDate | DATE | |
| kotlinx.datetime.LocalDateTime | TIMESTAMP | |
| enum class | VARCHAR2 | Can be customized by @KomapperEnum or komapper.enumStrategy. |
PostgreSQL - JDBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | numeric, decimal | |
| java.math.BigInteger | numeric, decimal | |
| java.sql.Array | array of data type | |
| java.sql.Blob | N/A | |
| java.sql.Clob | N/A | |
| java.sql.NClob | N/A | |
| java.sql.SQLXML | xml | |
| java.time.Instant | timestamp with time zone | |
| java.time.LocalDate | date | |
| java.time.LocalDateTime | timestamp | |
| java.time.LocalTime | time | |
| java.time.OffsetDateTime | timestamp with time zone | |
| java.util.UUID | uuid | |
| kotlin.Any | N/A | |
| kotlin.Boolean | boolean, bool | |
| kotlin.Byte | smallint | |
| kotlin.ByteArray | bytea | |
| kotlin.Double | double precision, float8 | |
| kotlin.Float | real | |
| kotlin.Int | integer, int, int4, serial | |
| kotlin.Long | bigint, int8, bigserial, serial8 | |
| kotlin.Short | smallint, int2, smallserial, serial2 | |
| kotlin.String | character varying, varchar, text | |
| kotlin.String | text | ClobString must be specified as alternate type. |
| kotlin.UByte | smallint, int2, smallserial, serial2 | |
| kotlin.UInt | bigint, int8, bigserial, serial8 | |
| kotlin.UShort | integer, int, int4, serial | |
| kotlinx.datetime.Instant | timestamp with time zone | |
| kotlinx.datetime.LocalDate | date | |
| kotlinx.datetime.LocalDateTime | timestamp | |
| enum class | character varying, varchar, text | Can be customized by @KomapperEnum or komapper.enumStrategy. |
PostgreSQL - R2DBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.postgresql.codec.Box | box | |
| io.r2dbc.postgresql.codec.Circle | circle | |
| io.r2dbc.postgresql.codec.Line | line | |
| io.r2dbc.postgresql.codec.Lseg | lseg | |
| io.r2dbc.postgresql.codec.Path | path | |
| io.r2dbc.postgresql.codec.Point | point | |
| io.r2dbc.postgresql.codec.Polygon | polygon | |
| io.r2dbc.postgresql.codec.Interval | interval | |
| io.r2dbc.postgresql.codec.Json | json, jsonb | |
| io.r2dbc.spi.Blob | bytea | |
| io.r2dbc.spi.Clob | text | |
| java.math.BigDecimal | numeric, decimal | |
| java.math.BigInteger | numeric, decimal | |
| java.time.Instant | timestamp with time zone | |
| java.time.LocalDate | date | |
| java.time.LocalDateTime | timestamp | |
| java.time.LocalTime | time | |
| java.time.OffsetDateTime | timestamp with time zone | |
| java.util.UUID | uuid | |
| kotlin.Any | N/A | |
| kotlin.Array | array of data type | |
| kotlin.Boolean | boolean, bool | |
| kotlin.Byte | smallint | |
| kotlin.ByteArray | bytea | |
| kotlin.Double | double precision, float8 | |
| kotlin.Float | real | |
| kotlin.Int | integer, int, int4, serial | |
| kotlin.Long | bigint, int8, bigserial, serial8 | |
| kotlin.Short | smallint, int2, smallserial, serial2 | |
| kotlin.String | character varying, varchar, text | |
| kotlin.String | text | ClobString must be specified as alternate type. |
| kotlin.UByte | smallint, int2, smallserial, serial2 | |
| kotlin.UInt | bigint, int8, bigserial, serial8 | |
| kotlin.UShort | integer, int, int4, serial | |
| kotlinx.datetime.Instant | timestamp with time zone | |
| kotlinx.datetime.LocalDate | date | |
| kotlinx.datetime.LocalDateTime | timestamp | |
| org.locationtech.jts.geom.Geometry | geometry | |
| enum class | character varying, varchar, text | Can be customized by @KomapperEnum or komapper.enumStrategy. |
SQL Server - JDBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| java.math.BigDecimal | decimal | |
| java.math.BigInteger | decimal | |
| java.sql.Array | N/A | |
| java.sql.Blob | varbinary(max) | |
| java.sql.Clob | text | |
| java.sql.NClob | N/A | |
| java.sql.SQLXML | xml | |
| java.time.Instant | datetimeoffset | |
| java.time.LocalDate | date | |
| java.time.LocalDateTime | datetime2 | |
| java.time.LocalTime | time | |
| java.time.OffsetDateTime | datetimeoffset | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | bit | |
| kotlin.Byte | smallint, tinyint | |
| kotlin.ByteArray | varbinary | |
| kotlin.Double | float | |
| kotlin.Float | real | |
| kotlin.Int | int | |
| kotlin.Long | bigint | |
| kotlin.Short | smallint | |
| kotlin.String | varchar, nvarchar | |
| kotlin.String | text | ClobString must be specified as alternate type. |
| kotlin.UByte | smallint | |
| kotlin.UInt | bigint | |
| kotlin.UShort | int | |
| kotlinx.datetime.Instant | datetimeoffset | |
| kotlinx.datetime.LocalDate | date | |
| kotlinx.datetime.LocalDateTime | datetime2 | |
| enum class | varchar, nvarchar | Can be customized by @KomapperEnum or komapper.enumStrategy. |
SQL Server - R2DBC
The following table shows the data type mapping:
| Kotlin Type | SQL Type | Description |
|---|---|---|
| io.r2dbc.spi.Blob | varbinary(max) | |
| io.r2dbc.spi.Clob | text | |
| java.math.BigDecimal | decimal | |
| java.math.BigInteger | decimal | |
| java.time.Instant | datetimeoffset | |
| java.time.LocalDate | date | |
| java.time.LocalDateTime | datetime2 | |
| java.time.LocalTime | time | |
| java.time.OffsetDateTime | N/A | |
| java.util.UUID | N/A | |
| kotlin.Any | N/A | |
| kotlin.Boolean | bit | |
| kotlin.Byte | smallint, tinyint | |
| kotlin.ByteArray | varbinary | |
| kotlin.Double | float | |
| kotlin.Float | real | |
| kotlin.Int | int | |
| kotlin.Long | bigint | |
| kotlin.Short | smallint | |
| kotlin.String | varchar, nvarchar | |
| kotlin.String | text | ClobString must be specified as alternate type. |
| kotlin.UByte | smallint | |
| kotlin.UInt | bigint | |
| kotlin.UShort | int | |
| kotlinx.datetime.Instant | datetimeoffset | |
| kotlinx.datetime.LocalDate | date | |
| kotlinx.datetime.LocalDateTime | datetimev | |
| enum class | varchar, nvarchar | Can be customized by @KomapperEnum or komapper.enumStrategy. |
Last modified November 23, 2023: Add descriptions about supported database versions (ab5b2f0)