Upgrade Guides

Compatibility Policy

Slick 3.4.0 requires 2.12 or 2.13 and Java 8, 11 or higher.

Slick version numbers consist of an epoch, a major and minor version, and possibly a qualifier (for milestone, RC and SNAPSHOT versions).

For release versions (i.e. versions without a qualifier), backward binary compatibility is guaranteed between releases with the same epoch and major version (e.g. you could use 2.1.2 as a drop-in replacement for 2.1.0 but not for 2.0.0). Binary compatibility is not preserved for slick-codegen, which is generally used at compile-time.

We do not guarantee source compatibility but we try to preserve it within the same major release. Upgrading to a new major release may require some changes to your sources. We generally deprecate old features and keep them around for a full major release cycle (i.e. features which become deprecated in 2.1.0 will not be removed before 2.2.0) but this is not possible for all kinds of changes.

Release candidates have the same compatibility guarantees as the final versions to which they lead. There are no compatibility guarantees whatsoever for milestones and snapshots.

Latest changes

See the generated tables of incompatible changes

Upgrade from 3.3.x to 3.4.0

The full list of bug fixes and changes in version 3.4.0 is available on github.

Dependency upgrades

Slick 3.4.0 updates the following upstream dependencies. If you use these libraries as part of your build, you should update your dependency versions to match:

Dependency Slick 3.3 depends on Slick 3.4 depends on Notes
com.typesafe:config 1.3.2 1.4.2 See the config library’s release notes for changes.
com.zaxxer:HikariCP 3.2.0 4.0.3 See the HikariCP changelog for changes. This only affects users who depend on the slick-hikaricp artifact.
org.scala-lang.modules:scala-collection-compat 2.0.0 2.6.0 Versions >= 2.0.0 should be binary-compatible, so no issues are expected. This only affects users building with Scala 2.11 or 2.12.

AsyncExecutor defaults

AsyncExecutor wraps the thread pool that Slick uses to run blocking I/O (such as database queries). The previous default constructor arguments could potentially cause deadlocks in some cases, so Slick 3.4 changes these to safer defaults. In most cases this should be a drop-in replacement but users are encourage to test performance carefully after upgrading. See issue #1938 for details.

PostgreSQL java.time mappings

The following bug fixes are highlighted here because they change the default mapping behaviour for some java.time columns in PostgreSQL:

  • java.time.Instant.MIN and java.time.Instant.MAX are now correctly mapped to -infinity and infinity respectively in PostgreSQL profile (#2237)
  • changes to handling of timezone part of java.time.Instant in PostgreSQL profile (#2005)

Upgrade from 3.4 to 3.5


ResultConverter is an internal interface for converting between values handled in JDBC and values handled in application code (case classes, etc.). While you most likely aren’t using it directly, you may need to call methods of this interface if you are override behavior of a profile or writing a new one.

In order to support a single insert statement with multiple rows, the set method now takes an offset parameter. If you have extended a profile and used the set method of this interface, you may need to specify 0 for the offset (unless the number of variable placeholders in the SQL dynamically changes).

Upgrade from 3.2 to 3.3

Create / Drop If Not Exists

There is no major changes in the API except for the addition of createIfNotExists and dropIfExistsPhase. This has only impact on database profile developers. Regular users are not impacted by it.

In other to support createIfNotExists and dropIfExistsPhase, the following changes were made:

  • slick.jdbc.JdbcStatementBuilderComponent#TableDDLBuilder.createTable receives not a checkNotExists: Boolean as argument
  • slick.jdbc.JdbcStatementBuilderComponent#TableDDLBuilder.dropTable receives not a ifExists: Boolean as argument
  • slick.sql.SqlProfile#DDL.apply has two more arguments createIfNotExists: Iterable[String] and dropIfExists: Iterable[String]

Support for java.time columns

Slick 3.3.0 profiles now supports java.time types as columns (for example, in Table column definitions).

If you already have custom mappings for these types, please review the formats in the tables below. These formats are the built-in Slick mappings, and they are the ones applied when you upgrade to Slick 3.3.0. That is, they take precedence over any MappedColumnType you may have defined for the java.time types.

The types are: Instant, LocalDate, LocalTime, LocalDateTime, OffsetTime, OffsetDateTime, and ZonedDateTime.

If you need to customise these formats, you can by extending a Profile and overriding the appropriate methods. For an example of this see: https://github.com/d6y/instant-etc/blob/master/src/main/scala/main.scala#L9-L45. Also of use will be an example of a full mapping, such as: https://github.com/slick/slick/blob/v3.3.0/slick/src/main/scala/slick/jdbc/JdbcTypesComponent.scala#L187-L365.

If you wish to upgrade your application to use the new formats, you may need to migrate your database columns to match the Slick column formats.

In the tables that follow there are many similarities between databases. However, not all databases can directly map the various java.time semantics. In these cases, a VARCHAR may have been used to store a formatted time representation. For more details see the description of Slick’s approach to these mappings.


Java Type SQL Type Example SQL Literal
java.time.Instant VARCHAR(254) '2019-02-03T18:20:28.660Z'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime VARCHAR(254) '18:20:28.661'
java.time.LocalDateTime TIMESTAMP '2019-02-03 18:20:28.661'
java.time.OffsetTime VARCHAR(254) '18:20:28.661Z'
java.time.OffsetDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant VARCHAR(254) '2019-02-03T18:20:28.660Z'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime VARCHAR(254) '18:20:28.661'
java.time.LocalDateTime TIMESTAMP '2019-02-03 18:20:28.661'
java.time.OffsetTime VARCHAR(254) '18:20:28.661Z'
java.time.OffsetDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant TIMESTAMP(9) WITH TIME ZONE '2019-02-03T18:20:28.660Z'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime VARCHAR '18:20:28.661'
java.time.LocalDateTime TIMESTAMP '2019-02-03 18:20:28.661'
java.time.OffsetTime VARCHAR '18:20:28.661Z'
java.time.OffsetDateTime VARCHAR '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime VARCHAR '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant TIMESTAMP(9) WITH TIME ZONE '2019-02-03 18:20:28.66'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime TIME(3) '18:20:28.661'
java.time.LocalDateTime TIMESTAMP '2019-02-03 18:20:28.661'
java.time.OffsetTime TIME(9) WITH TIME ZONE '18:20:28.661+0:00'
java.time.OffsetDateTime TIMESTAMP(9) WITH TIME ZONE '2019-02-03 18:20:28.661+0:00'
java.time.ZonedDateTime LONGVARCHAR '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant DATETIMEOFFSET(6) (convert(datetimeoffset(6), '2019-02-03 18:20:28.66 '))
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime TIME(6) (convert(time(6), '18:20:28.661'))
java.time.LocalDateTime DATETIME2(6) '2019-02-03 18:20:28.661'
java.time.OffsetTime VARCHAR(MAX) '18:20:28.661Z'
java.time.OffsetDateTime DATETIMEOFFSET(6) (convert(datetimeoffset(6), '2019-02-03 18:20:28.661 '))
java.time.ZonedDateTime VARCHAR(MAX) '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant TEXT '2019-02-03T18:20:28.660Z'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime TEXT '18:20:28.661'
java.time.LocalDateTime TEXT '2019-02-03T18:20:28.661'
java.time.OffsetTime TEXT '18:20:28.661Z'
java.time.OffsetDateTime TEXT '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime TEXT '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant TIMESTAMP(9) WITH TIME ZONE TO_TIMESTAMP_TZ('2019-02-03 18:20:28.660 +00', 'YYYY-MM-DD HH24:MI:SS.FF3 TZH')
java.time.LocalDate DATE TO_DATE('2019-02-03', 'SYYYY-MM-DD')
java.time.LocalTime VARCHAR2(254) '18:20:28.661'
java.time.LocalDateTime TIMESTAMP TO_TIMESTAMP('2019-02-03 18:20:28.661', 'YYYY-MM-DD HH24:MI:SS.FF3')
java.time.OffsetTime TIMESTAMP(6) WITH TIME ZONE TO_TIMESTAMP_TZ('1970-01-01 18:20:28.661 +0000', 'YYYY-MM-DD HH24:MI:SS.FF3 TZH:TZM')
java.time.OffsetDateTime TIMESTAMP(6) WITH TIME ZONE TO_TIMESTAMP_TZ('2019-02-03 18:20:28.661 +0000', 'YYYY-MM-DD HH24:MI:SS.FF3 TZH:TZM')
java.time.ZonedDateTime TIMESTAMP(6) WITH TIME ZONE TO_TIMESTAMP_TZ('2019-02-03 18:20:28.661 Europe/London', 'YYYY-MM-DD HH24:MI:SS.FF3 TZR')


Java Type SQL Type Example SQL Literal
java.time.Instant TIMESTAMP '2019-02-03 18:20:28.66'
java.time.LocalDate DATE '2019-02-03'
java.time.LocalTime TIME '18:20:28.661'
java.time.LocalDateTime TIMESTAMP '2019-02-03 18:20:28.661'
java.time.OffsetTime TIMETZ '18:20:28.661Z'
java.time.OffsetDateTime VARCHAR '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime VARCHAR '2019-02-03T18:20:28.661Z[Europe/London]'


Java Type SQL Type Example SQL Literal
java.time.Instant TIMESTAMP 1549218028660
java.time.LocalDate DATE 1549152000000
java.time.LocalTime VARCHAR(254) '18:20:28.661'
java.time.LocalDateTime TIMESTAMP 1549218028661
java.time.OffsetTime VARCHAR(254) '18:20:28.661Z'
java.time.OffsetDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z'
java.time.ZonedDateTime VARCHAR(254) '2019-02-03T18:20:28.661Z[Europe/London]'

Upgrade from 3.1 to 3.2

This section describes the changes that are needed when upgrading from Slick 3.1 to 3.2. If you are currently using an older version of Slick, please see the older [Slick Manuals] for details on other changes that may be required.

Profiles vs Drivers

Slick’s driver concept has been renamed to profile to end the confusion over Slick drivers vs JDBC drivers. All references to drivers from now on refer to JDBC drivers. Slick profiles can be either abstract (like JdbcProfile) or concrete (like H2Profile). The old names are still available as deprecated forwarders.

The renaming also affects configuration parameters (for example, for Databaseconfig). The old parameter names are still supported but their use will generate warnings at runtime.

Slick Extensions

The Slick Extensions package with additional profiles for Oracle, DB2 and SQL Server does not exist anymore for Slick 3.2. These profiles have been added to the core Slick package:

Database Action Scheduling

When configuring a database connection with a connection pool with a limited maximum size, you should always specify the correct size limit in Slick. This is necessary to prevent deadlocks when using transactions (or other pinned sessions). The configuration is done automatically when using Slick’s built-in HikariCP support. You only need to configure it manually if you use a connection pool through a JDBC DataSource or JNDI name.

The source code for this page can be found here.