Oracle Select From Table

"IT168 Technical Documentation" Since Oracle and HP launched Exadata, I have been very concerned about this product, and previously wrote an Oracle database machine introduced it. 　　Last year, Oracle and Sun merged to launch Oracle Exadata V2, which has several changes compared to previous generations: first, using sun hardware; second, it claims to support OLTP applications; third, Oracle 11g R2 offers more new features. Exadata S ...

ORA2PG is a Perl module that exports the Oracle database schema transfer to the PostgreSQL compatible schema. It connects the Oracle database, extracts the STI structure, and generates a SQL script that you can load into your PostgreSQL database, which dumps the database schema (table, view, sequence, index) of the foreign key into the PostgreSQL syntax without editing the generated code. It can be processed online or dump an Oracle file to the PostgreSQL database data, you can choose ...

Recently wanted to do a DataGrid function through PHP things, so that you can directly modify the contents of the database table, without the development of [new data page], [edit page], so looking for the Internet to find something similar A, open source, have paid, but basically are based on MySQL. Due to the need to connect to Oracle personally from the secondary development and page style phpMyDataGrid is still quite good. This article first introduced the use of MySQL-based methods, and then briefly introduce the Oracle connection (based on ...

Oracle defines a BLOB field for storing binary data, but this field does not hold true binary data, can only Gencun a pointer to the word, and then places the data in the LOB segment of Oracle to which the pointer points, and the LOB segment is part of the database's internal table. 　　Therefore, before manipulating an Oracle blob, the pointer (the locator) must be obtained before the BLOB data can be read and written. How do I get a blob pointer in a table? You can insert an empty B in a table using the INSERT statement first ...

ORA2PG is a Perl module that is used to export the Oracle database schema to the PostgreSQL compatible schema. It connects the Oracle database, extracts the STI structure, and generates a SQL script that you can load into your PostgreSQL database, which dumps the database schema (table, view, sequence, index) of the foreign key into the PostgreSQL syntax without editing the generated code. It can be processed online or dump an Oracle file to the PostgreSQL database data, you can ...

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

Method 1 delete yourtable where [id] not in (select max ([id]) from yourtable group by (name + value) b on a.id = b.id where b.id ...

As an outstanding representative of the Object relational database, Oracle is undoubtedly the most powerful. Whether it's the size of the database, the support of multimedia data types, the parallelism of SQL operations replication, or the security services, Oracle is much stronger than Sybase, Informix, Added to the latest version of the Oracle8.0.4 is to enhance the characteristics of this, but also introduced a number of new features, such as: Data partitioning (partitioning), Object-relational technology (objects relational T ...

SQL statement for querying and deleting duplicate records (i) For example, there is a field "name" in Table A, and the "name" value may be the same between different records, and now you need to query between the records in the table, the "name" value has duplicates, and select name, Count (*) from-a group by name has count (*) > 1 as ...

Logminer is an actual, useful analysis tool that Oracle has provided since 8i, which makes it easy to obtain specific content in Oracle Redo log files (archived log files), Logminer analysis tools are actually made up of a set of PL 　　SQL package and a number of dynamic views that can be used to analyze online logs and archive logs to obtain a database of past detailed, specific operations, very useful. 　　Why do you use Logminer? Mainly for the following reasons: When the database occurs ...