Skip to main content

Length

Definition​

The length method allows you to add the LENGTH function to the query. The LENGTH function is used to count the number of characters of a string. Additionally, you can add an encoding to this function and it will count the number of characters of a string in the given encoding. The string must be valid in this encoding.

There are 2 ways to call this method:

1. Calling from a KColumn or a KTableColumn​

The methods available to use this functionality calling from a KColumn or a KTableColumn are:

  • length(): It does not receive any parameters. The KColumn or KTableColumn that invokes the method will be the one supplied to the LENGTH function.
  • length(KEncoding encoding): Receives a KEncoding which will be supplied to the LENGTH function. The KColumn or KTableColumn that invokes the method will be the one supplied to the LENGTH function.

Example: ()​

Java code:

k
.select(
    APP_USER.EMAIL.length()
)
.from(APP_USER)
.multiple();

SQL generated:

SELECT
    LENGTH(au.email)
FROM app_user au

Parameters:

  • None

Example: (KEncoding)​

Java code:

k
.select(
    APP_USER.EMAIL.cast(bytea()).length(utf8())
)
.from(APP_USER)
.multiple();

SQL generated:

SELECT
    LENGTH(CAST(au.email AS BYTEA), 'UTF8')
FROM app_user au

Parameters:

  • None

2. Calling from the KFunction class​

The methods available to use this functionality calling from the KFunction class are:

  • length(KColumn kColumn): Receives a KColumn or a KTableColumn which will be supplied to the LENGTH function.
  • length(KValTextField kValTextField): Receives a KValTextField which will be supplied to the LENGTH function.
  • length(KColumn kColumn, KEncoding encoding): Receives a KColumn or a KTableColumn and a KEncoding which will be supplied to the LENGTH function.
  • length(KValTextField kValTextField, KEncoding encoding): Receives a KValTextField and a KEncoding which will be supplied to the LENGTH function.

To use this way, you need to import the static functions as follows:

import static com.myzlab.k.KFunction.*;

Example: (KColumn)​

Java code:

k
.select(
    length(APP_USER.EMAIL)
)
.from(APP_USER)
.multiple();

SQL generated:

SELECT
    LENGTH(au.email)
FROM app_user au

Parameters:

  • None

Example: (KValTextField)​

Java code:

k
.select(
    length(val("A short text"))
)
.single();

SQL generated:

SELECT LENGTH(?1)

Parameters:

  • ?1: "A short text"

Example: (KColumn, KEncoding)​

Java code:

k
.select(
    length(APP_USER.EMAIL.cast(bytea()), utf8())
)
.from(APP_USER)
.multiple();

SQL generated:

SELECT
    LENGTH(CAST(au.email AS BYTEA), 'UTF8')
FROM app_user au

Parameters:

  • None

Example: (KValTextField, KEncoding)​

Java code:

k
.select(
    length(val("a short text").cast(bytea()), utf8())
)
.single();

SQL generated:

SELECT LENGTH(CAST(?1 AS BYTEA), 'UTF8')

Parameters:

  • ?1: "A short text"