BlogJava-世界因你而精彩___vv-文章分类-DBhttp://www.blogjava.net/kingeleven/category/28094.html要么忙着生存，要么赶着去死！人总是要做点什么的!zh-cnThu, 03 Jan 2008 13:25:15 GMTThu, 03 Jan 2008 13:25:15 GMT60Java连接各种数据库的实例http://www.blogjava.net/kingeleven/articles/172523.htmlvvvvThu, 03 Jan 2008 09:29:00 GMThttp://www.blogjava.net/kingeleven/articles/172523.htmlhttp://www.blogjava.net/kingeleven/comments/172523.htmlhttp://www.blogjava.net/kingeleven/articles/172523.html#Feedback0http://www.blogjava.net/kingeleven/comments/commentRss/172523.htmlhttp://www.blogjava.net/kingeleven/services/trackbacks/172523.html1、Oracle8/8i/9i数据库（thin模式）

            
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();

            

            String url="jdbc:oracle:thin:@localhost:1521:orcl";

            

            //orcl为数据库的SID

            

            String user="test";

            

            String password="test";

            

            Connection conn= DriverManager.getConnection(url,user,password);


2、DB2数据库

            
Class.forName("com.ibm.db2.jdbc.app.DB2Driver ").newInstance();

            

            String url="jdbc:db2://localhost:5000/sample";

            

            //sample为你的数据库名

            

            String user="admin";

            

            String password="";

            

            Connection conn= DriverManager.getConnection(url,user,password);


3、Sql Server7.0/2000数据库

            
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();

            

            String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=mydb";

            

            //mydb为数据库

            

            String user="sa";

            

            String password="";

            

            Connection conn= DriverManager.getConnection(url,user,password);


4、Sybase数据库

            
Class.forName("com.sybase.jdbc.SybDriver").newInstance();

            

            String url =" jdbc:sybase:Tds:localhost:5007/myDB";

            

            //myDB为你的数据库名

            

            Properties sysProps = System.getProperties();

            

            SysProps.put("user","userid");

            

            SysProps.put("password","user_password");

            

            Connection conn= DriverManager.getConnection(url, SysProps);


5、Informix数据库

            
Class.forName("com.informix.jdbc.IfxDriver").newInstance();

            

            String url =

            

            "jdbc:informix-sqli://123.45.67.89:1533/myDB:INFORMIXSERVER=myserver;

            

            user=testuser;password=testpassword";

            

            //myDB为数据库名

            

            Connection conn= DriverManager.getConnection(url);


6、MySQL数据库

            
Class.forName("org.gjt.mm.mysql.Driver").newInstance();

            

            String url ="jdbc:mysql://localhost/myDB?

            
user=soft&password=soft1234&useUnicode=true&characterEncoding=8859_1"

            

            //myDB为数据库名

            

            Connection conn= DriverManager.getConnection(url);


7、PostgreSQL数据库

            
Class.forName("org.postgresql.Driver").newInstance();

            

            String url ="jdbc:postgresql://localhost/myDB"

            

            //myDB为数据库名

            

            String user="myuser";

            

            String password="mypassword";

            

            Connection conn= DriverManager.getConnection(url,user,password);



vv 2008-01-03 17:29 发表评论
]]>PostgreSQL 与 Oracle 相异点 （转）http://www.blogjava.net/kingeleven/articles/172487.htmlvvvvThu, 03 Jan 2008 06:56:00 GMThttp://www.blogjava.net/kingeleven/articles/172487.htmlhttp://www.blogjava.net/kingeleven/comments/172487.htmlhttp://www.blogjava.net/kingeleven/articles/172487.html#Feedback0http://www.blogjava.net/kingeleven/comments/commentRss/172487.htmlhttp://www.blogjava.net/kingeleven/services/trackbacks/172487.html ORACLE 与 PostgreSQL 相异点 NO 问题点 Oracle PostgreSQL 1 DUAL SELECT 1+1 FROM DUAL SELECT  1+1
或者
CREATE VIEW dual AS
      SELECT 'X'::VARCHAR(1) AS DUMMY
再 SELECT 1+1 FROM DUAL 2 NEXTVAL SELECT A_TABLE_SEQUENCE.NEXTVAL
FROM   DUAL SELECT NEXTVAL('A_TABLE_SEQUENCE')
FROM   DUAL 3 ROWNUM ①SELECT *
FROM  AGE_TYPE
WHERE ROWNUM<=5 ①SELECT *
FROM AGE_TYPE
LIMIT 5 OFFSET 0 ②SELECT *
FROM AGE_TYPE
WHERE CODE IS NOT NULL
AND ROWNUM<=5
ORDER BY CODE DESC ②SELECT  *
FROM
AGE_TYPE
WHERE CODE IS NOT NULL
ORDER BY CODE DESC
LIMIT 5 OFFSET 0 4 (+) ①SELECT *
FROM A_TABLE A , B_TABLE B
WHERE A.ID(+)=B.ID ①SELECT *
FROM A_TABLE A
RIGHT OUTER JOIN
B_TABLE B
ON A.ID=B.ID ②SELECT *
FROM A_TABLE A , B_TABLE B
WHERE A.ID(+)=B.ID
AND A.COL1='COL1_VALUE' ②SELECT *
FROM A_TABLE A
RIGHT OUTER JOIN B_TABLE B
ON A.ID=B.ID AND A.COL1='COL1_VALUE' ③SELECT *
FROM A_TABLE A, B_TABLE B,C_TABLE C,D_TABLE D
WHERE
A.ID=B.ID(+) AND
A.ID=C.ID(+) AND
A.COL1=D.COL1 ③SELECT *
FROM (A_TABLE A
LEFT OUTER JOIN B_TABLE B
ON A.ID=B.ID)
LEFT OUTER JOIN C_TABLE C
ON A.ID=C.ID,D_TABLE D
WHERE A.COL1=D.COL1 ④!!!
SELECT *
FROM A_TABLE A
WHERE A.COL1(+)=0 AND
 A.COL2(+) ='A_VALUE2' ④!!!
SELECT *
FROM A_TABLE A
WHERE A.COL1=0 AND
 A.COL2='A_VALUE2'
WHERE (A.COL1=0 OR A.COL1 IS NULL) AND
 (A.COL2='A_VALUE2' OR A.COL2 IS NULL) 5 AS SELECT A.COL1  A_COL1,
           A.COL2  A_COL2
FROM A_TABLE A SELECT A.COL1 AS A_COL1,
           A.COL2 AS A_COL2
FROM A_TABLE A 6 NVL SELECT NVL(SUM(VALUE11),0) FS_VALUE1,
            NVL(SUM(VALUE21),0) FS_VALUE2
FROM   FIELD_SUM  SELECT COALESCE(SUM(VALUE11),0) AS FS_VALUE1,
           COALESCE(SUM(VALUE21),0) AS FS_VALUE2
FROM   FIELD_SUM  7 TO_
NUMBER SELECT COL1
FROM A_TABLE
ORDER BY TO_NUMBER(COL1) SELECT COL1
FROM A_TABLE
ORDER BY TO_NUMBER(COL1,999999)
[注：'999999' ---- 6位数为COL1字段的长度] 8 DECODE SELECT DECODE(ENDFLAG,'1','A','B') ENDFLAG
FROM  TEST SELECT
(CASE ENDFLAG
WHEN '1' THEN 'A'
ELSE 'B' END) AS ENDFLAG
FROM TEST 9 时间
问题 UPDATE A_TABLE
SET ENTREDATE=SYSDATE UPDATE A_TABLE
SET ENTREDATE=TO_TIMESTAMP(CURRENT_TIMESTAMP,'YYYY-MM-DD HH24:MI:SS')
或者
UPDATE A_TABLE
SET ENTREDATE=CURRENT_TIMESTAMP SELECT TO_DATE('20010203','YYYY-MM-DD') AS DAY
FROM DUAL SELECT TO_DATE('20010203','YYYYMMDD') AS DAY
FROM DUAL
SELECT TO_DATE('20010203','YYYY-MM-DD') AS DAY
FROM DUAL SELECT TO_DATE(SYSDATE,'YYYY-MM-DD') AS DAY
FROM DUAL SELECT TO_DATE(CURRENT_DATE,'YYYY-MM-DD') AS DAY
FROM DUAL SELECT TO_DATE(SYSDATE,'YYYY/MM/DD') AS DAY
FROM DUAL SELECT TO_DATE(CURRENT_DATE,'YYYY/MM/DD') AS DAY
FROM DUAL 10 || SELECT NULL||'-'||NULL AS VALUES1
FROM DUAL
 SELECT COALESCE(NULL,'')||'-'||COALESCE(NULL,'') AS VALUES1
FROM DUAL
SELECT NULL||'-' ||NULL AS VALUES1
FROM DUAL 11 aggregate SELECT ROUND(AVG(SUM(BASICCNT1))) BASICCNT
FROM   ACCESS_INFO_SUM1_V
WHERE YEARCODE BETWEEN '200305' AND '200505'
GROUP BY SCCODE SELECT  ROUND(AVG(AIV.BASICCNT)) AS BASICCNT
FROM
    (SELECT SUM(BASICCNT1)      AS BASICCNT
    FROM   ACCESS_INFO_SUM1_V
    WHERE YEARCODE BETWEEN '200305' AND '200505'
    GROUP BY sccode
     ) AIV 12 「"」 ①SELECT LENGTH('') AS VALUE1 FROM DUAL
[Result]VALUE1=NULL ①SELECT LENGTH('') AS VALUE1 FROM DUAL
[Result]VALUE1=0 ②SELECT TO_DATE('','YYYYMMDD') AS VALUE2
FROM DUAL
[Result]VALUE2=NULL ②SELECT TO_DATE('','YYYYMMDD') AS VALUE2
FROM DUAL
[Result]VALUE2=0001-01-01 BC ③SELECT TO_NUMBER('',1) AS VALUE3 FROM DUAL
[Result]VALUE3=NULL ③SELECT TO_NUMBER('',1) AS VALUE3 FROM DUAL
[Result]不能执行 ④INSERT INTO TEST(VALUE4)VALUES('')
[Result]VALUE4=NULL (注：VALUE3字段为数值类型) ④INSERT INTO TEST(VALUE4)VALUES('')
[Result]VALUE4=0
 (注：VALUE4字段为数值类型) ⑤INSERT INTO TEST(VALUE5)VALUES('')
[Result]VALUE5=NULL (注：VALUE5字段为字符类型) ⑤INSERT INTO TEST(VALUE5)VALUES('')
[Result]VALUE5=''
 (注：VALUE5字段为字符类型,结果为长度为零的字符串) ⑥INSERT INTO TEST(VALUE6)VALUES(TO_DATE('','YYYYMMDD'))
[Result]VALUE6=NULL (注：VALUE6字段为时间类型) ⑥INSERT INTO TEST(VALUE6)VALUES(TO_DATE('','YYYYMMDD'))
[Result]VALUE6=0001-01-01 BC
 (注：VALUE7字段为时间类型) 13 CEIL SELECT CEIL(SYSDATE - TO_DATE('20051027 14:56:10','YYYYMMDD HH24:MI:SS')) AS DAYS
FROM DUAL SELECT
EXTRACT(DAY FROM (TO_TIMESTAMP(CURRENT_TIMESTAMP,'YYYY-MM-DD-HH24-MI-SS') -TO_TIMESTAMP('2005-10-27 14:56:10','YYYY-MM-DD-HH24-MI-SS') ))+1 AS DAYS
FROM DUAL 14 NULLIF 无NULLIF函数 SELECT NULLIF(VALUE1,VALUE2) AS COL1 FROM DUAL
[注]当VALUE1=VALUE2时，COL1=NULL 15 CONCAT CONCAT(CHAR,CHAR) 创建函数来解决
CREATE FUNCTION CONCAT(CHAR,CHAR)
RETURNS CHAR AS
        'SELECT $1 || $2' LANGUAGE 'sql'; 16 ADD_
MONTHS add_months(date, int) 创建函数来解决
CREATE FUNCTION add_months(date, int)
RETURNS date AS
'SELECT ($1 + ( $2::text || ''months'')::interval)::date;'
LANGUAGE 'sql' 17 LAST
_DAY LAST_DAY(DATE) 创建函数来解决
CREATE FUNCTION LAST_DAY(DATE)
RETURNS DATE AS
        'SELECT date(substr(text($1 +
                interval(''1 month'')),1,7)||''-01'')-1'
        LANGUAGE 'sql'; 18 MONTHS
_BETWEEN MONTH_BETWEEN(DATA,DATA) 创建函数来解决
CREATE FUNCTION MONTH_BETWEEN(DATA,DATA)
RETURNS NUMERIC AS
        'SELECT to_number((date($1)-
                           date($2)),''999999999'')/31'
        LANGUAGE 'sql'; 19 GRE~
ATEST GREATEST (LEAST) 创建函数来解决
CREATE OR REPLACE FUNCTION
   GREATEST(TEXT[]) RETURNS TEXT AS '
DECLARE
   ARRY ALIAS FOR $1;
   GREATEST TEXT;
BEGIN
   GREATEST := ARRY[1];
   FOR I IN 1 .. ARRAY_UPPER(ARRY,1) LOOP
      IF ARRY[I] > GREATEST THEN
        GREATEST := ARRY[I];
      END IF;
   END LOOP;
   RETURN GREATEST;
END;
' LANGUAGE 'PLPGSQL';

SELECT GREATEST( ARRAY['HARRY','HARRIOT','HAROLD'])
AS "Greatest"; 20 BITAND BITAND(int,int) SELECT 値 & 値; 21 子条件 　 在FROM子条件中字段须有列名，
处理方法用AS +别名 22 MINUS MINUS 以EXCEPT来替代 23 BIN_
TO_
NUM SELECT BIN_TO_NUM(1,0,1,0) AS VALUE1 FROM DUAL SELECT CAST(B'1010' AS INTEGER) AS VALUE1

vv 2008-01-03 14:56 发表评论
]]>oracle数据类型http://www.blogjava.net/kingeleven/articles/170253.htmlvvvvTue, 25 Dec 2007 03:04:00 GMThttp://www.blogjava.net/kingeleven/articles/170253.htmlhttp://www.blogjava.net/kingeleven/comments/170253.htmlhttp://www.blogjava.net/kingeleven/articles/170253.html#Feedback0http://www.blogjava.net/kingeleven/comments/commentRss/170253.htmlhttp://www.blogjava.net/kingeleven/services/trackbacks/170253.html    
  字段类型   中文说明   限制条件   其它说明    
  CHAR   固定长度字符串   最大长度2000   bytes          
  VARCHAR2   可变长度的字符串   最大长度4000   bytes     可做索引的最大长度749    
  NCHAR   根据字符集而定的固定长度字符串   最大长度2000   bytes          
  NVARCHAR2   根据字符集而定的可变长度字符串   最大长度4000   bytes          
  DATE   日期（日-月-年）   DD-MM-YY（HH-MI-SS）   经过严格测试，无千虫问题    
  LONG   超长字符串   最大长度2G（231-1）   足够存储大部头著作    
  RAW   固定长度的二进制数据   最大长度2000   bytes     可存放多媒体图象声音等    
  LONG   RAW   可变长度的二进制数据   最大长度2G   同上    
  BLOB   二进制数据   最大长度4G        
  CLOB   字符数据   最大长度4G        
  NCLOB   根据字符集而定的字符数据   最大长度4G        
  BFILE   存放在数据库外的二进制数据   最大长度4G        
  ROWID   数据表中记录的唯一行号   10   bytes   ********.****.****格式，*为0或1    
  NROWID   二进制数据表中记录的唯一行号   最大长度4000   bytes    
  NUMBER(P,S)   数字类型   P为整数位，S为小数位    
  DECIMAL(P,S)   数字类型   P为整数位，S为小数位    
  INTEGER   整数类型   小的整数    
  FLOAT   浮点数类型   NUMBER(38)，双精度    
  REAL   实数类型   NUMBER(63)，精度更高    
   
  这些数据类型的数字代码是多少？  
  如在dbf中  
  8   ----CHAR  
  12   -----NUMERIC  


vv 2007-12-25 11:04 发表评论
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