Oracle

1st day of last month 00:00:00 Select to_char (add_months (last_day (sysdate) + 1,-2), 'yyyy-mm-dd') | '00:00:00 'firstday from dual;   23:59:59 on the last day of last month (the last day of each month is the first day of next month minus one

Stored Procedures, functions, triggers, tables, etc. In PL/SQL: Export: Tool --> Export user object --> select multiple user objects to be exported, and select the path of the output script file (SQL file) --> export. A. SQL script file is

Syntax:Replace (char, search_string, replacement_string)  Usage: SetCharString inSearch_stringConvert all to stringsReplacement_stringAnd no matching strings will be changed.  Example: SQL> select Replace ('fgsgswsgs ', 'fk', 'J') from

If the not null restriction is added when varray is defined, the element of this varray cannot be null. Definition: Create or replace type integer_varrayAs varray (5) of integer not null;/   Then there is a PLSQL block as follows: Declare -- Declare

Today, Oracle 10 Gb is installed on your computer. Now we will introduce the installation process: Environment: OS: Win 2000 Server Mem: 250 m (haha is a little small, but there are still warnings during installation ~) DB: Oracle 10.2.0  1 ). You

Introduction: Data Pump User Guide10g introduced the latest data pump technology, allowing DBAs or developers to quickly move database metadata (object definition) and data to another Oracle database.Role of Data Pump Export Import (expdp and impdp)1

Oracle has launched the 11g database for more than a year. With the overall testing and evaluation of the 11g database by customers in various industries, the number of users who begin to upgrade to or deploy the Oracle 11g database is also

In Oracle, cursor is the most commonly used and most effective method to operate data.Oracle cursors can be divided into explicit and implicit Based on the declared methods of Oracle cursors.Explicit cursors are explicitly declared cursors. The

1. The foreign key constraint names in the Oracle database can be found in the user_constraints table. Constraint_type = 'R' indicates a foreign key constraint. 2. Run alter table table_name enable constraint constraint_name to enable the foreign

How to process Oracle BLOB fields in JDBC Source: Java resources Source: Hao congping How to process Oracle BLOB fields in JDBCWhy should I write this article?I encountered this problem in my project some time ago. It took me

1. How does one calculate data?Data Statistics are used to record the activity of data statistics, including data statistics and SQL statements, log on to Alibaba Cloud dataworks. Ii. Memory storage method of memory recordThere are two types: memory

I. Job ConceptA group of PL/SQL statements used to complete specific functions. It is written by industry experts, and can compare it with our work schedule in our daily work. It will start to work at a certain time in the future, or manually repeat

1. User conceptsThe user, that is, the user, is generally the "person" who accesses the Oracle database ". In Oracle, users can control various security parameters to maintain database security. These concepts include schema), permissions, roles,

In practice, the password operation of Oracle is implemented through profile, while the resource is controlled by the resource consumption group. profile is actually a limitation.You can use profile to control the use of passwords. Generally, there

MySQL replication and Oracle logical standby are both SQL apply. What is the difference in implementation?Binary log and redo transmission principlesMySQL replication can be easily used for application read expansion, and can also help MySQL

AndBitmap index is created on a single table, and bitmap join index is based on multi-table join. It is generally used to connect the foreign key columns of a fact table and the primary key columns of a dimension table. Some friends may be confused

ORA-00922: Option Missing or invalidError cause: the statement syntax is incorrect. For example, the name is incorrect or the keyword is incorrect. For non-standard names, they are generally created using double quotation marks.Solution:Identifier

Format:Select columnFrom table_nameStart with column = ValueConnect by prior parent primary key = Child foreign key Select lpad ('', 4 * (level-1) | Name, job, ID, super from EMPStart with super is nullConnect by prior id = super     Example:Raw

1. Environment Settings 1.1 Network Connection (both the source and target databases must be configured)Run Oracle Net Configuration Assistant to add a local service name. You can also directly modify the (tnsnames. ora) file. The content is as

CHAR and NCHAR are common types in Oracle databases, but the two data types are incompatible with each other. Here we will briefly discuss these two data types. In Oracle, the CHAR type is a fixed-length string type with a maximum length of 2000