--- layout: global title: Literals displayTitle: Literals license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --- A literal (also known as a constant) represents a fixed data value. Spark SQL supports the following literals: * [String Literal](#string-literal) * [Binary Literal](#binary-literal) * [Null Literal](#null-literal) * [Boolean Literal](#boolean-literal) * [Numeric Literal](#numeric-literal) * [Datetime Literal](#datetime-literal) * [Interval Literal](#interval-literal) ### String Literal A string literal is used to specify a character string value. #### Syntax ```sql '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 `👍`). #### Examples ```sql 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.| +---------+ ``` ### Binary Literal A binary literal is used to specify a byte sequence value. #### Syntax ```sql X { 'num [ ... ]' | "num [ ... ]" } ``` #### Parameters * **num** Any hexadecimal number from 0 to F. #### Examples ```sql SELECT X'123456' AS col; +----------+ | col| +----------+ |[12 34 56]| +----------+ ``` ### Null Literal A null literal is used to specify a null value. #### Syntax ```sql NULL ``` #### Examples ```sql SELECT NULL AS col; +----+ | col| +----+ |NULL| +----+ ``` ### Boolean Literal A boolean literal is used to specify a boolean value. #### Syntax ```sql TRUE | FALSE ``` #### Examples ```sql 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 ```sql [ + | - ] 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 ```sql 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: ```sql decimal_digits { [ BD ] | [ exponent BD ] } | digit [ ... ] [ exponent ] BD ``` double literals: ```sql decimal_digits { D | exponent [ D ] } | digit [ ... ] { exponent [ D ] | [ exponent ] D } ``` float literals: ```sql decimal_digits { F | exponent [ F ] } | digit [ ... ] { exponent [ F ] | [ exponent ] F } ``` While decimal_digits is defined as ```sql [ + | - ] { digit [ ... ] . [ digit [ ... ] ] | . digit [ ... ] } ``` and exponent is defined as ```sql 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 ```sql SELECT 12.578 AS col; +------+ | col| +------+ |12.578| +------+ 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 ```sql 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 ```sql 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 ```sql 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 as `Europe/Paris` **Note:** defaults to the session local timezone (set via `spark.sql.session.timeZone`) if `zone_id` is not specified. #### Timestamp Examples ```sql 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: ```sql INTERVAL [ ] ``` where `` can be a single field or in the field-to-field form: ```sql ::= TO | ``` 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 ``: ```sql ::= [ ] { | } ::= [ ] | ::= |