']; echo $ userid. "\ r \ n ";}}
2. problem analysis
1) suppose system_user only has 10 rows of data (u1, u2, u3, u4, u5, u6, u7, u8, u9, u10 ).2) at this time, five rows are taken each time. Two times.3) normally, the first page is taken (u1, u2, u3, u4, u5). Normally, the second page is taken (u6, u7, u8, u9, u10 ).4) If you finish the first page, the second page will be taken from the previous time gap.
Analysis of mysql paging data loss1. Problematic code
CleverCode finds that data is lost by page in mysql. As shown in the following code, the system_user table contains 4 million rows of data. In this case, all the userids in this table need to be obtained. In this case, only 20 thousand entries can be retrieved by page at a time.
// System user table (4 million rows of data) $ systemUserTable = new systemUserTable (); // 20000 $ pageSize = 20000; for ($ curPage = 1 ;; $ curPage ++) {$ SQL = "s
name value of the column (Can be Chinese)
5, modify the foreign key naming rules.Select Database->edit Current DBMSChoose scripts-"objects-" reference-"ConstnameYou can see that the value on the right is:
fk_%. u8:child%_%. u9:refr%_%. u8:parent%
Visible, the naming method is: ' Fk_ ' + 8-bit child table name + 9-bit reference name + 8-bit parent table name, which you can customize according to this pattern:
fk_%. u7:child%_relations_%.
from the Web is: Virtual installation of the SPARC architecture operating system via Simics. Operating systems that use VirtualBox or Vmvare to install a SPARC architecture do not work.2 Pre-Installation Preparation 2.1 Download the Solaris 8 ISO image file I chose the lower version of the Solaris 8 operating system image file because the version of Simics I used later was relatively low. The operating system installation files are downloaded in 2 ISO files, which are:Ftp://ftp.pl.freebsd.org/v
Intermatrix, an Australian company, said last week that it would launch its first UbuntuTouch-based tablet and begin to accept the reservation. Intermatrix is a small company with only five employees. the Ubuntu tablet named U7 was released this time as their first hardware product. How should such a small company produce hardware? This message has aroused attention in the industry. According to its internal staff, the company does not actually produc
Forum 2' (_ 9 B % I; U + V5 Z (D8 X: K K1 Q. NET Share to view locally enabled shares; u7]! G5 | ;@NET Share IPC $ enable IPC $ share to create the best computer self-learning Forum 6 {'? $ C "H: A" W5 s) dNET Share IPC $/del Delete IPC $ share I love Computer Technology Forum 6 j '}! W7 X: W7 Y2 V4 B! ONET Share C $/del Delete C: Share 4 E + R: N % H4 ^ $ x ? 6gNet user guest 12345 after logging in with the guest user, change the password to 123
It is really convenient to use powerdesigner for database design. The following are some common settings:
Additional: the toolbar is missing.
The palette (palette) shortcut toolbar is missing
The powerdesigner shortcut toolbar palette is gone. How can I open it again and find it?
I searched "powerdesigner graphic toolbar" online and found the way to retrieve the powerdesigner toolbar palette.Tools (toolbar)Customsize toolbars (custom toolbar)Select the palette (color palette) check box
Modify
Modify a foreign key naming rule
Select Database->edit Current DBMSChoose scripts-"objects-" reference-"ConstnameYou can see that the value on the right is:fk_%. u8:child%_%. u9:refr%_%. u8:parent%Visible, the naming method is: ' Fk_ ' + 8-bit child table name + 9-bit reference name + 8-bit parent table name, which you can customize according to this pattern:fk_%. u7:child%_relations_%. u7:parent%,You can c
example, because it displays Chinese characters correctly
Step Content Location Description
01:C1C2 Helloworld.java c1c2 refers to a iso8859_1 character, the word "medium" is taken apart
02:u3u4 Javac read u1u2 refers to a Unicode character
03:C1C2 GetBytes () The first step Java and the operating system to communicate (note or correct Oh!) )
04:b5b6 getBytes () The second step then returns a byte array (this is a critical step!). )
05:C12 New String () first Java and the operating system to
, with a maximum of 3 Mbps, with the demise of HD DVDs, DD + is basically invisible to Blu-ray discs, and only a demo Disc Made by Dolby itself. Dts hd hr is not much, because the bandwidth and space saved by DTs HD seem to be less attractive, and publishers seem reluctant to lose customers by using lossy compression audio tracks. These two kinds of lossy compression audio tracks also contain AC3 or DTS core data, and also have downward compatibility.The above four new audio specifications requi
TO U4; when authorizing an attribute column, you must specify the corresponding attribute column name.
[Example 5] GRANT the INSERT permission ON the table SC to the U5 user, and allow the user to grant this permission TO other users GRANT the insert on table SC TO U5 WITH GRANT OPTION;
After example 5 is executed, U5 not only has the INSERT permission ON the table SC, but also can spread this permission: [Example 6] grant insert on table SC TO U6 WITH GRANT OPTION; similarly, u6 can also GRANT
' => 'b7', '2' => 'i7', '3' => 'u7', '4' => 'u7', '5' => 'u7' );
For the preceding two-dimensional array, if you need to retrieve a segment, you need to know the position of the start and end of the segment in the array. Considering the particularity of the application, it only starts from the first array, in this two-dimensional array, retrieve the number of req
two-dimensional array value. The two-dimensional array data of the instance is as follows:
$arrayarray=array();
$array[1]=array('1'=>'b1','2'=>'i1','3'=>'u1','4'=>'u1','5'=>'u1');$array[2]=array('1'=>'b2','2'=>'i2','3'=>'u2','4'=>'u2','5'=>'u2');$array[3]=array('1'=>'b3','2'=>'i3','3'=>'u3','4'=>'u3','5'=>'u3');$array[4]=array('1'=>'b4','2'=>'i4','3'=>'u4','4'=>'u4','5'=>'u4');$array[5]=array('1'=>'b5','2'=>'i5','3'=>'u5','4'=>'u5','5'=>'u5');$array[6]=array('1'=>'b6','2'=>'i6','3'=>'u6
The last one said two ways to implement the verification code, let me talk about other methods.(a) Implementation of Chinese verification CodeIn fact, the implementation of Chinese verification code is almost the same as the alphanumeric, just the candidate letters and numbers to Chinese characters, and then the same random number of selected Chinese characters, the final output of the image. The Chinese character set chooses the commonly used Chinese character to be possible:String base = "\u76
DVDs, while dts hd hr is the opposite, with a maximum of 3 Mbps, with the demise of HD DVDs, DD + is basically invisible to Blu-ray discs, and only a demo Disc Made by Dolby itself. Dts hd hr is not much, because the bandwidth and space saved by DTs HD seem to be less attractive, and publishers seem reluctant to lose customers by using lossy compression audio tracks. These two kinds of lossy compression audio tracks also contain AC3 or DTS core data, and also have downward compatibility.
The ab
Modify foreign key naming rules
Choose database> edit current DBMS.Select scripts-> objects-> reference-> constnameThe value on the right is:
FK _ %. u8: child % _ %. U9: refr % _ %. u8: parent %
It can be seen that the naming method is: 'fk _ '+ 8-seat table name + 9-digit reference name + 8-digit parent table name. You can customize the following mode:
FK _ %. u7: child % _ relations _ %. u7: pare
12
With I420
yuv420p
Planar
3
12
With I420
yuvj420p
Planar
3
12
With I420, the difference is the color conversion formula, YUVJ uses the JPEG formula, the output data range [0..255], the I420 range is [16-240]
YV12
Planar
3
12
420. Y0y1. Y15 v0v1v2v3 U0U1U2U3 * Often use very many codecs to input and output in this format
yvu420p
Planar
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