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ASCII(str) ·µ»Ø×Ö·û´®strµÄ×î×óÃæ×Ö·ûµÄASCII´úÂëÖµ¡£Èç¹ûstrÊÇ¿Õ×Ö·û´®£¬·µ»Ø0¡£Èç¹ûstrÊÇNULL£¬·µ»ØNULL¡£
mysql> select ASCII('2');
-> 50
mysql> select ASCII(2);
-> 50
mysql> select ASCII('dx');
-> 100
Ò²¿É²Î¼ûORD()º¯Êý¡£
ORD(str) Èç¹û×Ö·û´®str×î×óÃæ×Ö·ûÊÇÒ»¸ö¶à×Ö½Ú×Ö·û£¬Í¨¹ýÒÔ¸ñʽ((first byte ASCII code)*256+(second byte ASCII code))[*256+third byte ASCII code...]·µ»Ø×Ö·ûµÄASCII´úÂëÖµÀ´·µ»Ø¶à×Ö½Ú×Ö·û´úÂë¡£Èç¹û×î×óÃæµÄ×Ö·û²»ÊÇÒ»¸ö¶à×Ö½Ú×Ö·û¡£·µ»ØÓëASCII()º¯Êý·µ»ØµÄÏàֵͬ¡£
mysql> select ORD('2');
-> 50

CONV(N,from_base,to_base) ÔÚ²»Í¬µÄÊý×Ö»ùÖ®¼ä±ä»»Êý×Ö¡£·µ»ØÊý×ÖNµÄ×Ö·û´®Êý×Ö£¬´Ófrom_base»ù±ä»»Îªto_base»ù£¬Èç¹ûÈκβÎÊýÊÇNULL£¬·µ»ØNULL¡£²ÎÊýN½âÊÍΪһ¸öÕûÊý£¬µ«ÊÇ¿ÉÒÔÖ¸¶¨ÎªÒ»¸öÕûÊý»òÒ»¸ö×Ö·û´®¡£×îС»ùÊÇ2ÇÒ×î´óµÄ»ùÊÇ36¡£Èç¹ûto_baseÊÇÒ»¸ö¸ºÊý£¬N±»ÈÏΪÊÇÒ»¸öÓзûºÅÊý£¬·ñÔò£¬N±»µ±×÷ÎÞ·ûºÅÊý¡£ CONVÒÔ64λµã¾«¶È¹¤×÷¡£
mysql> select CONV("a",16,2);
-> '1010'
mysql> select CONV("6E",18,8);
-> '172'
mysql> select CONV(-17,10,-18);
-> '-H'
mysql> select CONV(10+"10"+'10'+0xa,10,10);
-> '40'

BIN(N) ·µ»Ø¶þ½øÖÆÖµNµÄÒ»¸ö×Ö·û´®±íʾ£¬ÔÚ´ËNÊÇÒ»¸ö³¤ÕûÊý(BIGINT)Êý×Ö£¬ÕâµÈ¼ÛÓÚCONV(N,10,2)¡£Èç¹ûNÊÇNULL£¬·µ»ØNULL¡£
mysql> select BIN(12);
-> '1100'
OCT(N) ·µ»Ø°Ë½øÖÆÖµNµÄÒ»¸ö×Ö·û´®µÄ±íʾ£¬ÔÚ´ËNÊÇÒ»¸ö³¤ÕûÐÍÊý×Ö£¬ÕâµÈ¼ÛÓÚCONV(N,10,8)¡£Èç¹ûNÊÇNULL£¬·µ»ØNULL¡£
mysql> select OCT(12);
-> '14'

HEX(N) ·µ»ØÊ®Áù½øÖÆÖµNÒ»¸ö×Ö·û´®µÄ±íʾ£¬ÔÚ´ËNÊÇÒ»¸ö³¤ÕûÐÍ(BIGINT)Êý×Ö£¬ÕâµÈ¼ÛÓÚCONV(N,10,16)¡£Èç¹ûNÊÇNULL£¬·µ»ØNULL¡£
mysql> select HEX(255);
-> 'FF'

CHAR(N,...) CHAR()½«²ÎÊý½âÊÍΪÕûÊý²¢ÇÒ·µ»ØÓÉÕâЩÕûÊýµÄASCII´úÂë×Ö·û×é³ÉµÄÒ»¸ö×Ö·û´®¡£NULLÖµ±»Ìø¹ý¡£
mysql> select CHAR(77,121,83,81,'76');
-> 'MySQL'
mysql> select CHAR(77,77.3,'77.3');
-> 'MMM'

CONCAT(str1,str2,...) ·µ»ØÀ´×ÔÓÚ²ÎÊýÁ¬½áµÄ×Ö·û´®¡£Èç¹ûÈκβÎÊýÊÇNULL£¬·µ»ØNULL¡£¿ÉÒÔÓг¬¹ý


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mysql utf 8 ÂÒÂë½â¾ö======ÕýÈ·µÄ

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dz̸MySQLÂý²éѯÈÕÖ¾¼°microslow patch(msl patch)

       mysql(°üÀ¨ËùÓÐ5.*ϵÁÐ,5.1.21֮ǰ)µÄÂý²éѯÈÕ־ĬÈÏÊÇÒÔÃëΪµ¥Î»µÄ,¿ÉÒÔͨ¹ýset [session|global] long_query_time=1Õâ¸ö×îµÍÒ²¾ÍÊÇ¿ÉÒÔÉèÖõ½1Ãë,¶ÔÓÚ0.5,0.005Ö®Àà¾ÍÎÞÄÜΪÁ¦ÁË,Õâʱºò¿ÉÒÔÓÐmicroslow patch(msl patch)²¹¶¡À´Íê³ÉÕâÒ»¹¤×÷,Õâ¸ö¹¦Äܵĺô¦×ÔÈ»²»ÑÔ¶øÓ÷.
 &nb ......

MySQLµÄLOCK TABLES/UNLOCK TABLES

LOCK TABLES/UNLOCK TABLES ¾ä·¨
LOCK TABLES tbl_name [AS alias] {READ [LOCAL] | [LOW_PRIORITY] WRITE}
[, tbl_name [AS alias] {READ [LOCAL] | [LOW_PRIORITY] WRITE} ...]
...
UNLOCK TABLES
LOCK TABLES Ϊµ±Ç°Ïß³ÌËø¶¨±í¡£UNLOCK TABLES Êͷŵ±Ç°Ïß³ÌÓµÓеÄËùÓÐËø¶¨¡£µ±Ï̷߳¢³öÁíÒ»¸ö LOCK TABLES£¬»òµ±Óë·þ ......

cacti¼à¿ØmysqlÊý¾Ý¿âµÄ·½·¨

cacti ¼à¿Ø mysql
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Cactiez»òÕßcactiÖ÷»ú£º192.168.12.5
±»¼à¿ØmysqlÊý¾Ý¿âÖ÷»ú£º192.168.5.231
1. °²×°¼à¿Ø²å¼þ
cd /opt
wget http://mysql-cacti-templates.googlecode.com/files/mysql-cacti-templates-1.1.6.tar.gz
tar -xzvf mysql-cacti-templates-1.1.2.tar.gz
cp /opt/mysql-cacti-templates-1.1.2 ......

PHP/MYSQLʵÏÖ°´×Öĸ¼ìË÷

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| f_PY | cBegin | cEnd  |  
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| A    |  45217 | 45252 | & ......
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