Mysql应用sphinxql如何得到结果数及show meta的详细说明

发布时间：2020-12-12 02:57:27 所属栏目：MySql教程来源：网络整理

导读：《Mysql应用sphinxql如何得到结果数及show meta的详细说明》要点：本文介绍了Mysql应用sphinxql如何得到结果数及show meta的详细说明，希望对您有用。如果有疑问，可以联系我们。 mysql： select count(*) from main_index; MYSQL数据库但是这个在这里却报

《Mysql应用sphinxql如何得到结果数及show meta的详细说明》要点：
本文介绍了Mysql应用sphinxql如何得到结果数及show meta的详细说明，希望对您有用。如果有疑问，可以联系我们。

mysql：
select count(*) from main_index;MYSQL数据库

但是这个在这里却报语法错误.MYSQL数据库

第一种办法：
查文档得：
Aggregate functions (AVG(),MIN(),MAX(),SUM()) in column list clause are supported. Arguments to aggregate functions can be either plain attributes or arbitrary expressions. COUNT(*) is implicitly supported as using GROUP BY will add @count column to result set. Explicit support might be added in the future. COUNT(DISTINCT attr) is supported. Currently there can be at most one COUNT(DISTINCT) per query and an argument needs to be an attribute. Both current restrictions on COUNT(DISTINCT) might be lifted in the future.MYSQL数据库

也就是说只有在group by的时候才能用count(*),如：MYSQL数据库

代码如下:
select 1 as dummy,count(*) c from main_index group by dummy;
+------+--------+-------+--------+
| id | weight | dummy | @count |
+------+--------+-------+--------+
| 1001 | 1????? | 1 | 15659 |
+------+--------+-------+--------+

第二种办法
代码如下:
select * from main_index limit 0;
show meta;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| total???????? |? 67 |
| total_found?? |? 67 |
| time | 0.001? |
| keyword[0]???? |? ha |
| docs[0] | 67? |
| hits[0] | 115 |
+---------------+-------+

也就是说用show meta来得到这个total_found,这个就是总记录数.

下面我们来说一下show meta:
SHOW META shows additional meta-information about the latest query such as query time and keyword statistics:MYSQL数据库

也就是说它显示的是最近一次查询附加的一些信息,好比查询时间、关键字统计、总记录等.
MYSQL数据库

代码如下:
mysql> SELECT * FROM test1 WHERE MATCH('test|one|two');
+------+--------+----------+------------+
| id?? | weight | group_id | date_added |
+------+--------+----------+------------+
|??? 1 |?? 3563 |????? 456 | 1231721236 |
|??? 2 |?? 2563 |????? 123 | 1231721236 |
|??? 4 |?? 1480 |??????? 2 | 1231721236 |
+------+--------+----------+------------+
3 rows in set (0.01 sec)

mysql> SHOW META;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| total???????? | 3???? |
| total_found?? | 3???? |
| time????????? | 0.005 |
| keyword[0]??? | test? |
| docs[0]?????? | 3???? |
| hits[0]?????? | 5???? |
| keyword[1]??? | one?? |
| docs[1]?????? | 1???? |
| hits[1]?????? | 2???? |
| keyword[2]??? | two?? |
| docs[2]?????? | 1???? |
| hits[2]?????? | 2???? |
+---------------+-------+
12 rows in set (0.00 sec)

在PHP中如何调用?
代码如下:
<?php
//获取总记录个数
private function getTotalFound($conn) {
??? $sql = "show meta";
??? $total_result = @mysql_query ( $sql,$conn );
??? $totals = array ();
??? while ( ($row = mysql_fetch_assoc ( $total_result )) !== false ) {
??????? $totals [$row ['Variable_name']] = $row ['Value'];
??? }
??? return $totals;
}
?>

注意：如果代码中用了多个数据库连接的话,这个相应的conn必需传进来,否则是取不到结果的.

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