Literals
A literal (also known as a constant) represents a fixed data value. Spark SQL supports the following literals:
- String Literal
- Binary Literal
- Null Literal
- Boolean Literal
- Numeric Literal
- Datetime Literal
- Interval Literal
String Literal
A string literal is used to specify a character string value.
Syntax
[ r ] { 'char [ ... ]' | "char [ ... ]" }
Parameters
-
char
One character from the character set. Use
\
to escape special characters (e.g.,'
or\
). To represent unicode characters, use 16-bit or 32-bit unicode escape of the form\uxxxx
or\Uxxxxxxxx
, where xxxx and xxxxxxxx are 16-bit and 32-bit code points in hexadecimal respectively (e.g.,\u3042
forあ
and\U0001F44D
for👍
). -
r
Case insensitive, indicates
RAW
. If a string literal starts withr
prefix, neither special characters nor unicode characters are escaped by\
.
The following escape sequences are recognized in regular string literals (without the r
prefix), and replaced according to the following rules:
\0
->\u0000
, unicode character with the code 0;\b
->\u0008
, backspace;\n
->\u000a
, linefeed;\r
->\u000d
, carriage return;\t
->\u0009
, horizontal tab;\Z
->\u001A
, substitute;\%
->\%
;\_
->\_
;\<other char>
-><other char>
, skip the slash and leave the character as is.
The unescaping rules above can be turned off by setting the SQL config spark.sql.parser.escapedStringLiterals
to true
.
Examples
SELECT 'Hello, World!' AS col;
+-------------+
| col|
+-------------+
|Hello, World!|
+-------------+
SELECT "SPARK SQL" AS col;
+---------+
| col|
+---------+
|Spark SQL|
+---------+
SELECT 'it\'s $10.' AS col;
+---------+
| col|
+---------+
|It's $10.|
+---------+
SELECT r"'\n' represents newline character." AS col;
+----------------------------------+
| col|
+----------------------------------+
|'\n' represents newline character.|
+----------------------------------+
Binary Literal
A binary literal is used to specify a byte sequence value.
Syntax
X { 'num [ ... ]' | "num [ ... ]" }
Parameters
-
num
Any hexadecimal number from 0 to F.
Examples
SELECT X'123456' AS col;
+----------+
| col|
+----------+
|[12 34 56]|
+----------+
Null Literal
A null literal is used to specify a null value.
Syntax
NULL
Examples
SELECT NULL AS col;
+----+
| col|
+----+
|NULL|
+----+
Boolean Literal
A boolean literal is used to specify a boolean value.
Syntax
TRUE | FALSE
Examples
SELECT TRUE AS col;
+----+
| col|
+----+
|true|
+----+
Numeric Literal
A numeric literal is used to specify a fixed or floating-point number. There are two kinds of numeric literals: integral literal and fractional literal.
Integral Literal Syntax
[ + | - ] digit [ ... ] [ L | S | Y ]
Integral Literal Parameters
-
digit
Any numeral from 0 to 9.
-
L
Case insensitive, indicates
BIGINT
, which is an 8-byte signed integer number. -
S
Case insensitive, indicates
SMALLINT
, which is a 2-byte signed integer number. -
Y
Case insensitive, indicates
TINYINT
, which is a 1-byte signed integer number. -
default (no postfix)
Indicates a 4-byte signed integer number.
Integral Literal Examples
SELECT -2147483648 AS col;
+-----------+
| col|
+-----------+
|-2147483648|
+-----------+
SELECT 9223372036854775807l AS col;
+-------------------+
| col|
+-------------------+
|9223372036854775807|
+-------------------+
SELECT -32Y AS col;
+---+
|col|
+---+
|-32|
+---+
SELECT 482S AS col;
+---+
|col|
+---+
|482|
+---+
Fractional Literals Syntax
decimal literals:
decimal_digits { [ BD ] | [ exponent BD ] } | digit [ ... ] [ exponent ] BD
double literals:
decimal_digits { D | exponent [ D ] } | digit [ ... ] { exponent [ D ] | [ exponent ] D }
float literals:
decimal_digits { F | exponent [ F ] } | digit [ ... ] { exponent [ F ] | [ exponent ] F }
While decimal_digits is defined as
[ + | - ] { digit [ ... ] . [ digit [ ... ] ] | . digit [ ... ] }
and exponent is defined as
E [ + | - ] digit [ ... ]
Fractional Literals Parameters
-
digit
Any numeral from 0 to 9.
-
D
Case insensitive, indicates
DOUBLE
, which is an 8-byte double-precision floating point number. -
F
Case insensitive, indicates
FLOAT
, which is a 4-byte single-precision floating point number. -
BD
Case insensitive, indicates
DECIMAL
, with the total number of digits as precision and the number of digits to right of decimal point as scale.
Fractional Literals Examples
SELECT 12.578 AS col, TYPEOF(12.578) AS type;
+------+------------+
| col| type|
+------+------------+
|12.578|decimal(5,3)|
+------+------------+
SELECT 12.578E0 AS col, TYPEOF(12.578E0) AS type;
+------+------+
| col| type|
+------+------+
|12.578|double|
+------+------+
SELECT -0.1234567 AS col;
+----------+
| col|
+----------+
|-0.1234567|
+----------+
SELECT -.1234567 AS col;
+----------+
| col|
+----------+
|-0.1234567|
+----------+
SELECT 123. AS col;
+---+
|col|
+---+
|123|
+---+
SELECT 123.BD AS col;
+---+
|col|
+---+
|123|
+---+
SELECT 5E2 AS col;
+-----+
| col|
+-----+
|500.0|
+-----+
SELECT 5D AS col;
+---+
|col|
+---+
|5.0|
+---+
SELECT -5BD AS col;
+---+
|col|
+---+
| -5|
+---+
SELECT 12.578e-2d AS col;
+-------+
| col|
+-------+
|0.12578|
+-------+
SELECT -.1234567E+2BD AS col;
+---------+
| col|
+---------+
|-12.34567|
+---------+
SELECT +3.e+3 AS col;
+------+
| col|
+------+
|3000.0|
+------+
SELECT -3.E-3D AS col;
+------+
| col|
+------+
|-0.003|
+------+
Datetime Literal
A datetime literal is used to specify a date or timestamp value.
Date Syntax
DATE { 'yyyy' |
'yyyy-[m]m' |
'yyyy-[m]m-[d]d' |
'yyyy-[m]m-[d]d[T]' }
Note: defaults to 01
if month or day is not specified.
Date Examples
SELECT DATE '1997' AS col;
+----------+
| col|
+----------+
|1997-01-01|
+----------+
SELECT DATE '1997-01' AS col;
+----------+
| col|
+----------+
|1997-01-01|
+----------+
SELECT DATE '2011-11-11' AS col;
+----------+
| col|
+----------+
|2011-11-11|
+----------+
Timestamp Syntax
TIMESTAMP { 'yyyy' |
'yyyy-[m]m' |
'yyyy-[m]m-[d]d' |
'yyyy-[m]m-[d]d ' |
'yyyy-[m]m-[d]d[T][h]h[:]' |
'yyyy-[m]m-[d]d[T][h]h:[m]m[:]' |
'yyyy-[m]m-[d]d[T][h]h:[m]m:[s]s[.]' |
'yyyy-[m]m-[d]d[T][h]h:[m]m:[s]s.[ms][ms][ms][us][us][us][zone_id]'}
Note: defaults to 00
if hour, minute or second is not specified.
zone_id
should have one of the forms:
- Z - Zulu time zone UTC+0
+|-[h]h:[m]m
- An id with one of the prefixes UTC+, UTC-, GMT+, GMT-, UT+ or UT-, and a suffix in the formats:
+|-h[h]
+|-hh[:]mm
+|-hh:mm:ss
+|-hhmmss
- Region-based zone IDs in the form
area/city
, such asEurope/Paris
Note: defaults to the session local timezone (set via spark.sql.session.timeZone
) if zone_id
is not specified.
Timestamp Examples
SELECT TIMESTAMP '1997-01-31 09:26:56.123' AS col;
+-----------------------+
| col|
+-----------------------+
|1997-01-31 09:26:56.123|
+-----------------------+
SELECT TIMESTAMP '1997-01-31 09:26:56.66666666UTC+08:00' AS col;
+--------------------------+
| col |
+--------------------------+
|1997-01-30 17:26:56.666666|
+--------------------------+
SELECT TIMESTAMP '1997-01' AS col;
+-------------------+
| col|
+-------------------+
|1997-01-01 00:00:00|
+-------------------+
Interval Literal
An interval literal is used to specify a fixed period of time. The interval literal supports two syntaxes: ANSI syntax and multi-units syntax.
ANSI Syntax
The ANSI SQL standard defines interval literals in the form:
INTERVAL [ <sign> ] <interval string> <interval qualifier>
where <interval qualifier>
can be a single field or in the field-to-field form:
<interval qualifier> ::= <start field> TO <end field> | <single field>
The field name is case-insensitive, and can be one of YEAR
, MONTH
, DAY
, HOUR
, MINUTE
and SECOND
.
An interval literal can have either year-month or day-time interval type. The interval sub-type defines format of <interval string>
:
<interval string> ::= <quote> [ <sign> ] { <year-month literal> | <day-time literal> } <quote>
<year-month literal> ::= <years value> [ <minus sign> <months value> ] | <months value>
<day-time literal> ::= <day-time interval> | <time interval>
<day-time interval> ::= <days value> [ <space> <hours value> [ <colon> <minutes value> [ <colon> <seconds value> ] ] ]
<time interval> ::= <hours value> [ <colon> <minutes value> [ <colon> <seconds value> ] ]
| <minutes value> [ <colon> <seconds value> ]
| <seconds value>
Supported year-month interval literals and theirs formats:
<interval qualifier> |
Interval string pattern | An instance of the literal |
---|---|---|
YEAR | [+|-]'[+|-]y' |
INTERVAL -'2021' YEAR |
YEAR TO MONTH | [+|-]'[+|-]y-m' |
INTERVAL '-2021-07' YEAR TO MONTH |
MONTH | [+|-]'[+|-]m' |
interval '10' month |
Formats of supported day-time interval literals:
<interval qualifier> |
Interval string pattern | An instance of the literal |
---|---|---|
DAY | [+|-]'[+|-]d' |
INTERVAL -'100' DAY |
DAY TO HOUR | [+|-]'[+|-]d h' |
INTERVAL '-100 10' DAY TO HOUR |
DAY TO MINUTE | [+|-]'[+|-]d h:m' |
INTERVAL '100 10:30' DAY TO MINUTE |
DAY TO SECOND | [+|-]'[+|-]d h:m:s.n' |
INTERVAL '100 10:30:40.999999' DAY TO SECOND |
HOUR | [+|-]'[+|-]h' |
INTERVAL '123' HOUR |
HOUR TO MINUTE | [+|-]'[+|-]h:m' |
INTERVAL -'-123:10' HOUR TO MINUTE |
HOUR TO SECOND | [+|-]'[+|-]h:m:s.n' |
INTERVAL '123:10:59' HOUR TO SECOND |
MINUTE | [+|-]'[+|-]m' |
interval '1000' minute |
MINUTE TO SECOND | [+|-]'[+|-]m:s.n' |
INTERVAL '1000:01.001' MINUTE TO SECOND |
SECOND | [+|-]'[+|-]s.n' |
INTERVAL '1000.000001' SECOND |
ANSI Examples
SELECT INTERVAL '2-3' YEAR TO MONTH AS col;
+----------------------------+
|col |
+----------------------------+
|INTERVAL '2-3' YEAR TO MONTH|
+----------------------------+
SELECT INTERVAL -'20 15:40:32.99899999' DAY TO SECOND AS col;
+--------------------------------------------+
|col |
+--------------------------------------------+
|INTERVAL '-20 15:40:32.998999' DAY TO SECOND|
+--------------------------------------------+
Multi-units Syntax
INTERVAL interval_value interval_unit [ interval_value interval_unit ... ] |
INTERVAL 'interval_value interval_unit [ interval_value interval_unit ... ]' |
Multi-units Parameters
-
interval_value
Syntax:
[ + | - ] number_value | '[ + | - ] number_value'
-
interval_unit
Syntax:
YEAR[S] | MONTH[S] | WEEK[S] | DAY[S] | HOUR[S] | MINUTE[S] | SECOND[S] | MILLISECOND[S] | MICROSECOND[S] Mix of the YEAR[S] or MONTH[S] interval units with other units is not allowed.
Multi-units Examples
SELECT INTERVAL 3 YEAR AS col;
+-------+
| col|
+-------+
|3 years|
+-------+
SELECT INTERVAL -2 HOUR '3' MINUTE AS col;
+--------------------+
| col|
+--------------------+
|-1 hours -57 minutes|
+--------------------+
SELECT INTERVAL '1 YEAR 2 DAYS 3 HOURS';
+----------------------+
| col|
+----------------------+
|1 years 2 days 3 hours|
+----------------------+
SELECT INTERVAL 1 YEARS 2 MONTH 3 WEEK 4 DAYS 5 HOUR 6 MINUTES 7 SECOND 8
MILLISECOND 9 MICROSECONDS AS col;
+-----------------------------------------------------------+
| col|
+-----------------------------------------------------------+
|1 years 2 months 25 days 5 hours 6 minutes 7.008009 seconds|
+-----------------------------------------------------------+