oracle sql keywords list

Oracle table connection modes (SQL optimization) 1. NESTED LOOP For a small subset of connected data, nested loop connection is a good choice. The nested loop is used to scan a table. Every time a record is read, it is searched in another table based on the index. Without an index, it is generally not nested loops. Generally, in the nested loop, the result set of the driver table meeting the condition is no

You may be running an Oracle 10g Release 2 database server, but supporting some applications may have been written very early. Data tables created prior to Oracle 8i typically have a long data type to store large text. With the introduction of the large Object (LOB) data type, the long and long raw data types are discarded. If you are copying a data table that uses a Long data type, then using the CREATE t

We know that every RDBMS has its own characteristics in SQL. So today, let's take a look at the characteristics of Oracle, which deserves our attention. Feature 1:Oracle analysis functions and window functions:Syntax: FUNCTION_NAME (OVER (For example:Sum (sal) over (partition by deptno order by ename rows ...)Where sum is the function name,Over () is a keyword. T

maximum and minimum values for a columnSELECT * FROM table_name WHERE COLUMN_NAME = (SELECT MAX (column_name) from table_name);SELECT * FROM table_name WHERE COLUMN_NAME = (SELECT MIN (column_name) from table_name);3.SUM ([distinct l all] expr) MIN ([distinct l all] expr)Sum function that returns the value of the specified column andSELECT SUM (all column_name) from table_name [WHERE CONDITION];4.COUNT ([distinct l all] expr) MIN ([distinct l all] expr)Returns the number of records for a queryS

Label:The first is the problem of fuzzy query, I started with the following conditions: SELECT * from the user where name like '% #value #% '. But how can not, as if also reported wrong. Later on the internet found a solution, is to use $ to replace the # number.1> write: Like '% $value $% ' can be,2> also found another method, but that method I tried for a long time, is not, the method is: like '% ' | | #value # | | '% ', the query came out of the results are actually all. Later on the internet

The external table introduced in Oracle 9i allows you to map a sequential text file to an Oracle table definition. Once you have defined an external table, you can apply all the functionality of the SQL SELECT statement-including parallel queries-to handle it. External tables are based on Sql*loader, but the syntax for

There are three types of data changes in the database: insert, update, and delete ). These operations are common to developers. There are three types of data changes in the database: insert, update, and delete ). These operations are common to developers. There are three main types of data changes in the database: insert data ( InsertOperations and precautions UpdateOperations and precautions DeleteOperations and precautions Through the study in this chapter, readers can learnInsert/update/

Value List specifies the values of each column. The column names and values must correspond to each other. 1.2Batch insert TableC_studentsThe data structure and content are as follows. SQL> select * from c_students; STUDENT_ID STUDENT_NAME We can use the followingSQLThe statement inserts new data into the table. The new data comes from the table.StudentsMediumStudent_idTop 10 student information.

connection fileUnder the "D:\Program files\instantclient_12_1\admin" path, create the Tnsnames.ora file and add the database connection configuration information in the format as follows:FAVBLOG-TST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.1.100) (PORT = 1521)) (Connect_data = ( SID = favccxx) (SERVER = dedicated))) Favblog-dev = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.16 8.1.101) (PORT = 1521)) (Connect_data = (SID = ORCL) (SERVER = dedicated))3. Configure P

expression after the while is re-determined to be true, only if the Boolean expression after the while is false. To end the entire loop loop.The syntax for the statement structure is as follows:[C, while ... Loop structureSql>--while...loopsql> declare 2 v_rlt Number (8): =-3; 3 begin 4 3.FOR ... Loop structureFor ... The Loop statement can traverse an integer of a range that is enclosed by the For and Loop keywords. When the loop is first

Oracle + mybatis uses dynamic SQL to implement batch insert when the inserted fields are uncertain. oraclemybatis Recently, the project encountered a very tangled problem. Due to the business relationship, the database data table cannot be determined, and fields may be added during use, this causes a lot of trouble to me during insert. First, let's take a look at how I implemented it: Because the data tabl