我正在编写一个存储过程,以便将数据插入tbluser表。以下是我的存储过程:
BEGIN
/* Check if user already exits*/
DECLARE user_count INT;
select count(*) from tblusers into user_count where name = 'joseph';
/* Calculate the row count of table and calculate the id for new row*/
DECLARE totalrows,current_id INT;
我在旧网站上工作,在日志文件中发现了这个错误:
Invalid SQL: SELECT COUNT(*) AS color_count FROM colors WHERE id IN (on,on) ;
mysql error: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near
'on,on) ' at line 1
php代码如下所示:
$que
我一直在犯错误。如何在MySQL中运行这样的查询?
UPDATE Events SET eventName = 'hi' IF ROW_COUNT() = 0 INSERT INTO EVENTS (eventName) VALUES (hi);
基本上我想要更新,但是如果没有要更新的数据,我会插入数据。有什么办法可以做到这一点吗?
编辑1获取此错误
mysql> UPDATE Events
-> SET eventName = 'hi';
IF ROW_COUNT() = 0
THEN
DELETE FROM Events
我猜想,我以绝对错误的方式使用了--这些MySQL控制结构(参见下面)。问题可能在MySQL查询中,但我不确定.
MySQL错误:您的SQL语法出现了错误;请检查与MySQL服务器版本对应的手册,以获得使用“IF@MySQL> 1000”的正确语法,然后在第1行的sys_proc_err中选择@actRecords:=COUNT(id)。
#include <mysql.h>
// other includes, declarations for mysql... etc.
int main() {
mysql_init(&mysql);
mysql_r
Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C ...
这是代码
function db_result_to_array($result) {
$res_array = array();
for ($count=0; $row = mysql_fetch_array($result); $count++) {
$res_array[$count] = $row;
}
return $res_array;
}
所以,错误在这一行
for ($coun
mysql> select count(id) total from applicants;
+-------+
| total |
+-------+
| 0 |
+-------+
1 row in set (0.00 sec)
mysql> select count(id) total from jobs;
+-------+
| total |
+-------+
| 0 |
+-------+
1 row in set (0.00 sec)
mysql> select count(id) total from applicants union s
我尝试了两种方法,但在mysql中失败了。
/*see top 50% students, but this sql can't work*/
select * from student_table order by chinese_score desc limit count(*) * 0.5 ;
/*also can't work*/
set @num= floor((select count(*) from test.student_score)*0.5);
select * from student_table order by chinese_score desc
如果您的唯一目标是检查php (true或false)中是否存在行,那么最好的方法是什么?
选项1?
$result = mysql_query("SELECT * FROM users WHERE id = '1'");
$num_rows = mysql_num_rows($result);
if ($num_rows == 1)
// one user, like it should be.
else
// do something else
选项2?
$query = mysql_query("select count(1)
我正在尝试优化我的查询,我有以下代码:
<?php
$counter = mysql_query("SELECT COUNT(*) AS c FROM table");
$row = mysql_fetch_array($counter);
$count = $row["c"];
if($count>500){
mysql_query("DELETE FROM table");
}
?>
我尝试了下面的语法作为测试,它起了作用:
Select case when (Select count(*) as t from `table
SELECT COUNT(*) INTO @count FROM `tableName` WHERE `id` = OLD.id;
WHILE @count > -1 DO
SET @count = @count - 1;
/* loop logic in here */
END WHILE;
我有这个SQL,但是当我运行它时,我得到一个错误( Syntax),MySQL说它在WHILE @count > -1 DO SET @count = @count - 1;附近。我尝试过将while封装在BEGIN ... END;块中,但这丝毫不影响它。
由于MySQL
我正在尝试理解mysqli扩展,并做了谷歌,但得到的信息很少,除了php.net,这是有帮助的。
现在,在所有这些之后,我正在尝试使用mysql扩展实现我所能实现的功能,如下所示:
// MYSQL STYLE OF fetching array, query limit and perform total row count all at once
$sql = "SELECT SQL_CALC_FOUND_ROWS *, post.id as pid, bla bla FROM account ORDER BY pid ASC". $eb["array"]
指令'register_long_arrays,在PHP5.3.28中,警告出现: mysql_num_rows()期望参数1为资源,布尔值在xxx/mysql.php第534行给出
534引用此行:$count = mysql_num_rows($resource);
function CountResult($resource=null)
{
if ($resource === null) {
$this->SetError('Resource is a null object');
return false;
我正在尝试获取mysql查询的计数。这很简单:
SELECT COUNT(id) FROM table WHERE [insert rule here] GROUP BY grouper
问题是因为最后的group by,我最终得到了每个组的行数,而我只是想要一个总数。
为了做到这一点,我将把结果放在一个查询的数组中,它看起来更像这样:
$res = mysql_query(SELECT * FROM table WHERE [insert rule here] GROUP BY grouper)
$count = mysql_num_rows($res);
这行得通,但我只想用COUNT。
我正在尝试执行一个包含以下代码的.bat文件
@echo off
setlocal EnableDelayedExpansion
C:\Windows\System32\cmd.exe /c ""C:\Program Files\MySQL\MySQL Server
5.7\bin\mysql.exe" -u root -p88adb88 -h localhost -Ddatabase_1 -e
"delete from job where id in (select * from (SELECT MAX(id) AS id FROM job
where
我已经看了很多次代码,并重写了它,但仍然不知道如何修复这个错误。
有6-10行;
function login_check ($email, $password) {
$email = mysql_real_escape_string ($email);
$login_query = mysql_query("SELECT COUNT(`user_id`) as `count`,`user_id` FROM `users` WHERE `email`='$email' AND `password`='".md5($password)."'
我有一个mysql例程,它不起作用:
delimiter #;
create procedure ancien ()
BEGIN
declare postname CHAR;
declare ID INT;
declare count INT;
declare counter INT DEFAULT 0;
select count(*) INTO @count FROM network_2_posts;
LOOP: 'posts'
set counter = counter + 1;
IF counte
为什么只有在通过Resque调度程序执行时才会出现错误?
我不知道为什么在通过resque-调度程序调用时只选择用户名。我希望选中users表的所有列.
由resque-调度程序调用的作业如下所示:
class UserLicenseJob
@queue = :some_queue
def self.perform(*args)
users = User.license_count_exceeded
# Do something to the 'users'
end
end
错误日志如下所示:
failed: #<ActiveRecord::
在mysql中,我有以下内容:
结构Table
id(int primary key)
name(varchar 100 unique)
价值:
id name
1 test
2 test1
我有两个问题:
1) SELECT count(*) FROM Table WHERE name='test'
2)如果count选择行== 0秒查询INSERT INTO Table (name) VALUES ('test')
我知道这可能是有用的:
$res = mysql(SELECT count(*) as count FROM Table WHERE
这是我的触发器,我得到了MySQL语法错误。我想减少sms_index表sms_count列值的余额。
CREATE TRIGGER sms_log_update AFTER UPDATE ON sms_index
FOR EACH ROW
BEGIN
IF NEW.approved_status = '1' THEN
UPDATE sms_package SET balance = (balance - OLD.sms_count) WHERE group_id = OLD.ins_group_id;
END IF;
END;
我目前正在设置一个监视器来监视云SQL DB中的慢查询。我构建了一个自定义查询来让进程在SQL服务器上运行,因为目前缓慢的查询监控直到进程完成才会报告。为了在5分钟内每隔15-20秒(或在DD中配置的任何内容)检查一次当前运行的查询,我在DD代理的配置中设置了以下内容。
custom_queries:
- query: SELECT COUNT(*) as processes FROM INFORMATION_SCHEMA.PROCESSLIST WHERE TIME >
(5 * 60 * 1000);
columns:
在创建触发器时,我会得到以下错误:
您的SQL语法出现了错误;请检查与您的MySQL服务器版本对应的手册,以获得在第3行附近使用的正确语法
这是我的疑问:
CREATE TRIGGER reserved BEFORE INSERT ON Reserv
FOR EACH ROW BEGIN
DECLARE trip_id integer;
DECLARE free integer;
DECLARE count integer;
set @free := (select place_free from Trips where id = trip_id);