=
(等号)运算符
适用于: Databricks SQL
Databricks Runtime
如果 true
等于 expr1
,则返回 expr2
;否则返回 false
。 此函数是 ==(双等号)运算符的同义函数。
语法
expr1 = expr2
参数
返回
一个 BOOLEAN
。
示例
> SELECT 2 = 2;
true
> SELECT 1 = '1';
true
> SELECT true = NULL;
NULL
> SELECT equal_null(true, NULL);
false
> SELECT NULL = NULL;
NULL
> SELECT equal_null(NULL, NULL);
true
-- By default string comparisons are trailing space sensitive
-- This can be overridden by using the COLLATE clause
> SELECT 'hello' = 'hello ' AS default,
'hello' = 'hello ' COLLATE UTF8_BINARY AS utf8_binary,
'hello' = 'hello ' COLLATE UTF8_BINARY_RTRIM AS rtrim;
default utf8_binary rtrim
------- ----------- -----
false false true
-- By default string comparisons are trailing space sensitive
-- This can be overridden by using the COLLATE clause
> SELECT 'world ' = 'world ' AS default,
'world ' = 'world ' COLLATE UTF8_BINARY AS utf8_binary,
'world ' = 'world ' COLLATE UTF8_BINARY_RTRIM AS rtrim;
default utf8_binary rtrim
------- ----------- -----
false false true