=={{Admon/obsolete}} <big><big> PostgreSQL Adapter for NexJ - Working Inside Schema 'test'==</big></big> ===1- Initializing the SQL environment===* ''PostgreSQLAdapter.java'': When a connection is first established, this initial SQL statement should execute in MySQL, which is not the case for PostgreSQL, so it the implementation was commented outremoved from PostgreSQLAdapter.java:

* ''postgresql_create.sql'': Also This file was just created as a copy of mysql_create.sql, which was not the case for PostgreSQL again. So the same line should in the file is removed for now. The file itself may be commented out in postgresql_createdeleted later, if there was no need for it.sql Name of the script, which file is being used to create tables returned in the database 'test':'''getCreateEtcScriptName()'''''' in '''PostgreSQLSchemaManager.java'''

 == 2- DATA DEFINITION LANGUAGE _ DDL ===== CREATING SCHEMA ===* List of Files needed to be modified *:src- [[ PostgreSQL_Adapter-nexj/SchemaManger | PostgreSQLSchemaManager.java ]] --- ([[SchemaBackup]]) // Extends SQLSchemaManager.java - class for reading, creating and upgrading the database schema: test- [[ PostgreSQL_Adapter-nexj/SchemaMangerTest | PostgreSQLSchemaManagerTest.java]] // Extends SQLSchemaManagerTest.java: Script - scripts are being processed through SQLDataTest.java * <u><code> CREATE TABLE </code></u>: 1- DATA TYPE: data types are changed in '''''<code> appendColumnType() </code>''''' based on each jdbc type's equivalent in PostgreSQL. ::*[http://db.apache.org/ddlutils/databases/postgresql.html mapping JDBC data types to PostgreSQL data types]::*[http://en.wikibooks.org/wiki/Converting_MySQL_to_PostgreSQL#Data_Types comparison between Postgre and MySQL data types] : 2- STORAGE ENGINE: In MySQL, the storage engine is set to a transactional safe engine such as [http://www.wikivs.com/wiki/MySQL_vs_PostgreSQL#MySQL:InnoDB InnoDB], whereas PostgreSQL has a single built in engine. So, implementation of '''''<code> appendTableSuffix() </code> ''''' in PostgreSQLManager.java was removed:3- CHARACTER SET: In MySQL, the character set should be defined when creating a table. Whereas in PostgreSQL when a database is created, the character set is set to 'UTF8' by default. : 4- AUTO INCREMENT: PostgreSQL doesn't support 'auto_increment' as some other databases for a unique identifier column. There are two ways around this, 1- To create a 'sequence', 2- Use SERIAL, which is a macro around 'sequence'. SERIAL is an 'integer' and a 'sequence, with the column default to the sequences next value. As of postgreSQL 7.3, to make a serial column unique, it should be specified as a unique constraint or a primary key. More info @ [[PostgreSQL_Adapter-nexj/Resources#Mapping_Data_Types.2C_Metadata | PostgreSQL Resources]]:<source lang=java>/* MySQL version of creating table script */ create table test.RangeTest( id int auto_increment not null, s varchar(1) character set utf8 null, bin varbinary(1) null, n int null, n1 tinyint unsigned null, l bigint null, "DEC" decimal(10,5) null, f float null, d double null, tm datetime null, b boolean null, constraint RangeTest_PK primary key(id))engine=InnoDB character set = utf8</source>:

create /* PostgreSQL version of creating table script */ CREATE TABLE test.AccountRangeTest( id binary(16) serial not null, contactId binarys text null, bin bytea null, n integer null, n1 smallint null, l bigint null, "DEC" decimal(1610,5) not null, f double precision null, d double precision null, tm timestamp null, b boolean null, constraint Account_PK RangeTest_PK primary key(id) )ENGINE=InnoDB CHARACTER SET=utf8; // Using SERIAL is another way to work around 'sequence'//CREATE SEQUENCE test.RangeTest_id_seq;// PostgreSQL version with no ENGINE and CHARACTERALTER TABLE test.RangeTest ALTER COLUMN id SET DEFAULT NEXTVAL('test.RangeTest_id_seq');

=== Working with Data Types ===: *<u><code> CREATE TEXT TABLE test.xxx </code></u>:: data types are changed The implementation in '''''<code> appendColumnTypecrateTextTable() </code> in ''PostgreSQLSchemaManager.java'' based on each jdbc type' is removed for now (base class's equivalent in version is being called).:TODO To be checked if it's the case for PostgreSQLas well.:* <u><code>CREATE INDEX </code></u> : The implementation in '''''<code> crateTextTable createIndex() </code> in file ''PostgreSQLSchemaManager.java''' is removed for now (base class's version is being called).: TODO To be checked if it's the case for PostgreSQL as well.:Note- If there was a complain for duplicate index name, a fully qualified name can be used. Just note that PostgreSQL doesn't like fully qualified name as <code>CREATE INDEX testtable.xxx indexname</code> for indexes or triggers, instead a '_' can be used: <code>table_indexname</code> : * <code> <u> CREATE Trigger test.xxx </u></ code>:TODO To be checked if it's triggers are needed for PostgreSQL as well as MySQL. It's not an abstract method in '''''SQLSchemaManager.java'''''.: <code>'''''createTrigger()'''''</code> is added to '''''MySQLSchemaManager.java''''' ===UPDGRADING SCHEMA===* List of Files needed to be modified :src - [[ PostgreSQL_Adapter-nexj/SchemaManger | PostgreSQLSchemaManager.java ]] --- ([[SchemaBackup]]) // Extends SQLSchemaManager.java - class for reading, creating and upgrading the database schema: [[ PostgreSQL_Adapter-nexj/Upgrade | main.upgrade ]]: test- [[ PostgreSQL_Adapter-nexj/SchemaMangerTest | PostgreSQLSchemaManagerTest.java]] // Extends SQLSchemaManagerTest.java: Script - postgresql_drop.sql * <u><code> DROP TABLE </code></u> * <u><code> INSERT INTO TABLE </code></u>

{|class="collapsible collapsed" style="border-style:solid;border-width:thin;border3-color:black"!alignDATA MANIPULATION LANGUAGE _ DML ="left" style="background-color:SteelBlue; font-weight:bold;border-style:solid;border-width:thin;padding: 2px 2px 2px 2px;"| '''* List of Files needed to Configure''' |- |be modified[[sampleProj]]:src:: - [[ PostgreSQL_Adapter-nexj/Adapter | PostgreSQLAdapter.java ]] // Extends SQLAdapter.java - SQL Persistence adapter, responsible for regular data queries (insert, select, delete):: [[ PostgreSQL_Adaptertest-nexj/SchemaManger | PostgreSQLSchemaManager.java ]] // Extends SQLSchemaManager.java - class for reading, creating and upgrading the database schema:: [[ PostgreSQL_Adapter-nexj/Upgrade | main.upgrade ]]: test:: [[ PostgreSQL_Adapter-nexj/AdapterTest | PostgreSQLAdapterTest.java ]]] // Extends SQLAdapterTest.java:: [[ PostgreSQL_Adapter-nexj/SchemaMangerTest | PostgreSQLSchemaManagerTest.java ]] // Extends SQLSchemaManagerTest.java

:: postgresql_setuppostgresql_insert.sql:: TO be cond'|}