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san', '1', '2', 8 ); Insert into student (id, name, sex, grade, age) values (2, 'lily', '0', '1', 11 ); Insert into student (id, name, sex, grade, age) values (3, 'wang wu', '1', '2', 9 ); Insert into student (id, name, sex, grade, age) values (4, 'Liu 2', '0', '4', 8 ); Insert into student (id, name, sex, grade, age) values (5, 'Han liu', '0', '3', 6 ); -- Insert into sexcode Insert into sexcode (dm, mc) values ('1', 'male '); Insert into sexcode (dm, mc) values ('0', 'female '); -- Insert i
of the other Oracle server) (port = port number)) ) (Connect_data = (service_name = Other Oracle Server service name) ) )' Where the name of the data chain is the service name added to the local Oracle Database Console (Oracle Enterprise Manager Console) tree nodeThe table tablename statement to
In most cases, this dynamically generated SQL query statement is written as follows: Copy Code code as follows: Select a table. field 1,a table. field 2,b table. field returns, C table. field returns from Table A, B table, C table [where a table, B table, C Table Association and respective conditional statement] But the disadvantage of this approach is that the business logic program
Oracle Database multi-Table query instance and Oracle database instanceFlute product: the number of columns is added, and the number of rows is multiplied. SQL> -- equivalent connection SQL> -- Query employee information: employe
);insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno) values (7900, 'JAMES', 'CLERK', 7698, to_date('03-12-1981', 'dd-mm-yyyy'), 950, null, 30);insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno) values (7902, 'FORD', 'ANALYST', 7566, to_date('03-12-1981', 'dd-mm-yyyy'), 3000, null, 20);insert into EMP (empno, ename, job, mgr, hiredate, sal, comm, deptno) values (7934, 'MILLER', 'CLERK', 7782, to_date('23-01-1982', 'dd-mm-yyyy'), 1300, null, 10); Note:T
-defined integrity : For example: In student form the age of secondary school students cannot be greater than 60 (user-defined conditions) 3. Connection Query The connection in Oracle is the same as MySQL, there are also self connected query, outer connection (including left outer connection, right outer connection, full outer connection), and internal connection
Oracle data query using C # for SQL or ASP. When the query condition exists in Chinese , because the data server and client/natively have different character sets , the data table has data, but the data is not queried. However, data queries can be made using the same string as the
1. add, delete, modify, and query DML (DataManipulationLanguage-data operation language) in Oracle can be executed under the following conditions: insert data into the table, modify existing data, and delete existing data. A transaction is composed of DML statements that complete several tasks. 2. Insert data operations to list columns in the default sequence of columns. In the INSERT clause 1. add, delete,
The number/frequency of SQL queries in ORACLE and the number of SQL queries in oracle In ORACLE Database Application optimization, the execution Frequency/frequency of an SQL statement is also frequently concerned, because the exe
How to compile efficient SQL query statements and SQL statementsOverview How can I write SQL query statements with high performance? Two Methods: creating reasonable indexes and writing efficient SQL statements Basic Principles of
ORACLE multi-Table query optimization and ORACLE Optimization ORACLE has a high-speed buffer concept. This high-speed buffer is used to store the executed SQL statements. Therefore, oracle has to do a lot of work when executing
After learning how to use ibatis over the past few days, I suddenly used fuzzy queries and dynamic multi-condition queries. I tried it for a long time based on my own ideas and did not solve this problem. The first problem is fuzzy query. At the beginning, I used the following conditions: Select * from user where name like '% # value # % '. but why not? It seems that an error has been reported. later, I found a solution on the Internet, which is t
join Cdms_organizationOn Cdms_organization.organizationid=tfinfo.parentid; The above SQL is Yungo taught me, although not their own writing, but according to this idea, I found that I was right, but not the understanding of Oracle is not enough to write Today, the main thing is to let me re-understand the Oracle query
; registry> parameter file The character set must be consistent, but the language settings can be different. We recommend that you use English for language settings. If the character set is zhs16gbk, The nls_lang can be American_America.zhs16gbk. Involves three character sets,1. Character Set on the El server side;2. Character Set of oracle client;3. dmp file character set. During data import, the three character sets must be consistent before the da
Oracle multi-Table query optimization and Oracle Optimization ORACLE has a high-speed buffer concept. This high-speed buffer is used to store the executed SQL statements. Therefore, oracle has to do a lot of work when executing
to use sql/xml build functions such as XmlElement, Xmlforest, and XMLAgg (). XQuery will be more efficient than these functions in the 2nd edition of Oracle database G. Specifically, using the Ora:view XQuery function inside an XQuery expression, you can query an existing relational table or view and build XML on the fly, eliminating the need to explicitly creat
FROM cte a INNER JOIN TBL_TEST b ON a.id = b.PID)SELECT * FROM cte;The above two methods have all found positive results. The Start With of the first method is equivalent to the part above union all of the second method. connect by is equivalent to the part below union all. The CTE method is portable. It is also supported by SQL SERVER and DB2. You can refer to the following articles for more examples of the CTE method:
Example:1) Find employee information with a salary above 3000SELECT *Froms_emp Ewhere e.salary>3000;2) Find all information about employees who are known as CarmenSELECT * FROM S_emp EWheree.first_name = ' Carmen ';"Oracle SQL keywords, table names, column names, etc. are case insensitive, and the values in the records are case sensitive"3) Find out the employee information without performanceSELECT * FROM
query character sets on oracle server There are many ways to find the character set of the oracle server. The intuitive query method is as follows: SQL> select userenv ('language') from dual; USERENV ('language ') ---------------------------------------------------- SIMPLIF
USED_PERSENTFROM (SELECT TABLESPACE_NAME, SUM (BYTES)/1024/1024 TOTAL_MBFROM DBA_TEMP_FILESGroup by TABLESPACE_NAME) TMP_TBS,(SELECT TMP_USED.TABLESPACE,TMP_USED.SEGTYPE,SUM (TMP_USED.BLOCKS * PARA. DB_BLOCK_SIZE)/1024/1024 USED_MBFrom v $ SORT_USAGE TMP_USED,(Select value DB_BLOCK_SIZEFrom v $ PARAMETERWhere name = 'db _ BLOCK_SIZE ') PARAGroup by TMP_USED.TABLESPACE, TMP_USED.SEGTYPE) USED_TOTWHERE TMP_TBS.TABLESPACE_NAME = USED_TOT.TABLESPACE (+)Group by TMP_TBS.TABLESPACE_NAME, USED_TOT.SEG
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