mysql中关于 like ,not like 的用法时不能显示null的数据
当使用like 或者not like的时候,如果字段内容为null,则查询结果会不显示为null的内容,此时应加 or 字段名称 is null,如下:
select * from table where (fileld like "%你好%" or field is null)
但是尽量减少null值,可以给字段设置默认值''
当使用like 或者not like的时候,如果字段内容为null,则查询结果会不显示为null的内容,此时应加 or 字段名称 is null,如下:
select * from table where (fileld like "%你好%" or field is null)
但是尽量减少null值,可以给字段设置默认值''
最近不知道什么情况,用户数据在同一秒内会出现2条甚至多条数据一样的情况,为了避免重复数据插入,需要将重复数据删除后,在添加联合索引。
一,先看一下重复数据总量
SELECT mobile, CONCAT(mobile,UNIX_TIMESTAMP(created_at)) as unit_mobile, count(mobile) as num FROM estimate_user GROUP BY unit_mobile HAVING num > 1;
确认手机号后,把这批手机号数据导出备份,方便后面验证;
二、删除重复数据
DELETE from estimate_user where id not in (select t.max_id from (select max(id) as max_id from users group by CONCAT(mobile,UNIX_TIMESTAMP(created_at)) HAVING num > 1) as t );
三、验证重复手机号是否存在后创建联合索引
<?php
/**
function createPoster($config=[] ,$filename=""){
//如果要看报什么错,可以先注释调这个header
if(empty($filename)) header("content-type: image/png");
$imageDefault = array(
'left'=>0,
'top'=>0,
'right'=>0,
'bottom'=>0,
'width'=>100,
'height'=>100,
'opacity'=>100
);
$textDefault = array(
'text'=>'',
'left'=>0,
'top'=>0,
'fontSize'=>32, //字号
'fontColor'=>'255,255,255', //字体颜色
'angle'=>0,
);
$background = $config['background'];//海报最底层得背景
//背景方法
$backgroundInfo = getimagesize($background);
$backgroundFun = 'imagecreatefrom'.image_type_to_extension($backgroundInfo[2], false);
$background = $backgroundFun($background);
$backgroundWidth = imagesx($background); //背景宽度
$backgroundHeight = imagesy($background); //背景高度
$imageRes = imageCreatetruecolor($backgroundWidth,$backgroundHeight);
$color = imagecolorallocate($imageRes, 0, 0, 0);
imagefill($imageRes, 0, 0, $color);
// imageColorTransparent($imageRes, $color); //颜色透明
imagefilledrectangle($imageRes, 0, 0, 399, 29, $color);
imagecopyresampled($imageRes,$background,0,0,0,0,imagesx($background),imagesy($background),imagesx($background),imagesy($background));
//处理了图片
if(!empty($config['image'])){
foreach ($config['image'] as $key => $val) {
$val = array_merge($imageDefault,$val);
$info = getimagesize($val['url']);
$function = 'imagecreatefrom'.image_type_to_extension($info[2], false);
if($val['stream']){ //如果传的是字符串图像流
$info = getimagesizefromstring($val['url']);
$function = 'imagecreatefromstring';
}
$res = $function($val['url']);
$resWidth = $info[0];
$resHeight = $info[1];
//建立画板 ,缩放图片至指定尺寸
$canvas=imagecreatetruecolor($val['width'], $val['height']);
imagefill($canvas, 0, 0, $color);
//关键函数,参数(目标资源,源,目标资源的开始坐标x,y, 源资源的开始坐标x,y,目标资源的宽高w,h,源资源的宽高w,h)
imagecopyresampled($canvas, $res, 0, 0, 0, 0, $val['width'], $val['height'],$resWidth,$resHeight);
$val['left'] = $val['left']<0?$backgroundWidth- abs($val['left']) - $val['width']:$val['left'];
$val['top'] = $val['top']<0?$backgroundHeight- abs($val['top']) - $val['height']:$val['top'];
//放置图像
imagecopymerge($imageRes,$canvas, $val['left'],$val['top'],$val['right'],$val['bottom'],$val['width'],$val['height'],$val['opacity']);//左,上,右,下,宽度,高度,透明度
}
}
//处理文字
if(!empty($config['text'])){
foreach ($config['text'] as $key => $val) {
$val = array_merge($textDefault,$val);
list($R,$G,$B) = explode(',', $val['fontColor']);
$fontColor = imagecolorallocate($imageRes, $R, $G, $B);
$val['left'] = $val['left']<0?$backgroundWidth- abs($val['left']):$val['left'];
$val['top'] = $val['top']<0?$backgroundHeight- abs($val['top']):$val['top'];
imagettftext($imageRes,$val['fontSize'],$val['angle'],$val['left'],$val['top'],$fontColor,$val['fontPath'],$val['text']);
}
}
//生成图片
if(!empty($filename)){
$res = imagejpeg ($imageRes,$filename,90); //保存到本地
imagedestroy($imageRes);
if(!$res) return false;
return $filename;
}else{
imagejpeg ($imageRes); //在浏览器上显示
imagedestroy($imageRes);
}}
//调用方法
//调用方法
$config = [
'image'=>[
[
'url'=>'WechatIMG392.jpeg', //二维码资源
'stream'=>0,
'left'=>100,
'top'=>268,
'right'=>0,
'bottom'=>0,
'width'=>178,
'height'=>178,
'opacity'=>100
]
],
'background'=>'back.jpeg', //背景图,
'text' =>[
[
'text'=>$text,
'left'=>162,
'top'=>460,
'fontPath'=>$font, //字体文件
'fontSize'=>$fontSize, //字号
'fontColor'=>$color, //字体颜色
'angle'=>0,
],
[
'text'=>$text2,
'left'=>162,
'top'=>590,
'fontPath'=>$font, //字体文件
'fontSize'=>$fontSize, //字号
'fontColor'=>$color, //字体颜色
'angle'=>0,
],
]];
$filename = date("Ymd").'.jpg';
createPoster($config,$filename);//直接生成图片
//createPoster($config);//浏览器直接预览
/**
function postJson($url, $data_string) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json; charset=utf-8',
'Content-Length: ' . strlen($data_string))
);
ob_start();
curl_exec($ch);
$return_content = ob_get_contents();
ob_end_clean();
$return_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
return array('code'=>$return_code, 'result'=>$return_content);}
当php通过file_get_contents 获取html页面内容时,对于html的空格 无法用exlpode(" ",$content);转换成功,可以使用一下方法转换
$content = preg_replace("/(\s|\ \;| |\xc2\xa0)/"," ",$content);