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drop table if exists t1;
drop database if exists mysqltest;
CREATE TABLE t1 (a INT, b INT, c INT, d INT);
INSERT INTO t1 VALUES (1,3,0,NULL),(2,2,0,NULL),(3,4,0,NULL),(4,2,0,NULL);
SELECT * FROM t1;
a b c d
1 3 0 NULL
2 2 0 NULL
3 4 0 NULL
4 2 0 NULL
UPDATE t1 SET c=LAST_VALUE(@last_a:=a,@last_b:=b,@last_c:=c,1), d=4211 WHERE c=0 ORDER BY b DESC LIMIT 1;
SELECT @last_a, @last_b, @last_c;
@last_a @last_b @last_c
3 4 0
SELECT * FROM t1;
a b c d
1 3 0 NULL
2 2 0 NULL
3 4 1 4211
4 2 0 NULL
DROP TABLE t1;
SELECT LAST_VALUE(@last_a:=1,@last_b:=1);
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def LAST_VALUE(@last_a:=1,@last_b:=1) 3 1 1 N 32897 0 63
LAST_VALUE(@last_a:=1,@last_b:=1)
1
select @last_b;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def @last_b 8 20 1 Y 32896 0 63
@last_b
1
SELECT LAST_VALUE(@last_a:=1,@last_b:=1.0);
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def LAST_VALUE(@last_a:=1,@last_b:=1.0) 246 4 3 N 32897 1 63
LAST_VALUE(@last_a:=1,@last_b:=1.0)
1.0
select @last_b;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def @last_b 246 83 3 Y 32896 38 63
@last_b
1.0
SELECT LAST_VALUE(@last_a:=1,@last_b:="hello");
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def LAST_VALUE(@last_a:=1,@last_b:="hello") 253 5 5 N 1 39 8
LAST_VALUE(@last_a:=1,@last_b:="hello")
hello
select @last_b;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def @last_b 251 16777215 5 Y 0 39 8
@last_b
hello
SELECT date(LAST_VALUE(@last_a:=1,@last_b:="2001-02-03"));
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def date(LAST_VALUE(@last_a:=1,@last_b:="2001-02-03")) 10 10 10 Y 128 0 63
date(LAST_VALUE(@last_a:=1,@last_b:="2001-02-03"))
2001-02-03
select @last_b;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def @last_b 251 16777215 10 Y 0 39 8
@last_b
2001-02-03
SELECT LAST_VALUE(@last_a:=1,@last_b:="2001-02-03",NULL);
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def LAST_VALUE(@last_a:=1,@last_b:="2001-02-03",NULL) 6 0 0 Y 32896 0 63
LAST_VALUE(@last_a:=1,@last_b:="2001-02-03",NULL)
NULL
select @last_b;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def @last_b 251 16777215 10 Y 0 39 8
@last_b
2001-02-03
SELECT LAST_VALUE();
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 1
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