conversion.rst

Type Conversion Functions

Table of contents

• CAST

CAST

Description

Usage: cast(expr as dateType) cast the expr to dataType. return the value of dataType. The following conversion rules are used:

Src/Target	STRING	NUMBER	BOOLEAN	TIMESTAMP	DATE	TIME
STRING		Note1	Note1	TIMESTAMP()	DATE()	TIME()
NUMBER	Note1		v!=0	N/A	N/A	N/A
BOOLEAN	Note1	v?1:0		N/A	N/A	N/A
TIMESTAMP	Note1	N/A	N/A		DATE()	TIME()
DATE	Note1	N/A	N/A	N/A		N/A
TIME	Note1	N/A	N/A	N/A	N/A

Note1: the conversion follow the JDK specification.

Cast to string example:

os> source=people | eval `cbool` = CAST(true as string), `cint` = CAST(1 as string), `cdate` = CAST(CAST('2012-08-07' as date) as string) | fields `cbool`, `cint`, `cdate`
fetched rows / total rows = 1/1
+---------+--------+------------+
| cbool   | cint   | cdate      |
|---------+--------+------------|
| true    | 1      | 2012-08-07 |
+---------+--------+------------+

Cast to number example:

os> source=people | eval `cbool` = CAST(true as int), `cstring` = CAST('1' as int) | fields `cbool`, `cstring`
fetched rows / total rows = 1/1
+---------+-----------+
| cbool   | cstring   |
|---------+-----------|
| 1       | 1         |
+---------+-----------+

Cast to date example:

os> source=people | eval `cdate` = CAST('2012-08-07' as date), `ctime` = CAST('01:01:01' as time), `ctimestamp` = CAST('2012-08-07 01:01:01' as timestamp) | fields `cdate`, `ctime`, `ctimestamp`
fetched rows / total rows = 1/1
+------------+----------+---------------------+
| cdate      | ctime    | ctimestamp          |
|------------+----------+---------------------|
| 2012-08-07 | 01:01:01 | 2012-08-07 01:01:01 |
+------------+----------+---------------------+

Cast function can be chained:

os> source=people | eval `cbool` = CAST(CAST(true as string) as boolean) | fields `cbool`
fetched rows / total rows = 1/1
+---------+
| cbool   |
|---------|
| True    |
+---------+