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Type Conversion Functions

Table of contents

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  |
+-------+