org.melati.poem.dbms

Class Postgresql

java.lang.Object

org.melati.poem.dbms.AnsiStandard

org.melati.poem.dbms.Postgresql

All Implemented Interfaces:

Dbms

public class Postgresql
extends AnsiStandard

A Driver for Postgresql. See http://www.postgresql.org/ Backwards compatabilty Previous (7.4) versions allowed single quotes to be quoted using C style escaping. In version 9.1 you need to explicitly allow this escaping by configuring the server: backslash_quote = on standard_conforming_strings = off

Constructor Summary

Constructors

Constructor and Description
Postgresql() Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	canDropColumns() Whether this DBMS can drop columns.
SQLPoemType<?>	defaultPoemTypeOfColumnMetaData(ResultSet md) An Object Id PoemType.
SQLPoemException	exceptionForUpdate(Table<?> table, String sql, boolean insert, SQLException e) An exception appropriate for expressing what really went wrong during a write to the db.
String	getBinarySqlDefinition(int size) Accommodate different treatment of different sized binary data.
String	getStringSqlDefinition(int size) Accommodate String/Text distinction.
String	preparedStatementPlaceholder(PoemType<?> type) Accommodate casting in placeholders.

Methods inherited from class org.melati.poem.dbms.AnsiStandard

alterColumnAddCommentSQL, alterColumnNotNullableSQL, alterTableAddCommentSQL, booleanTrueExpression, canBeIndexed, canRepresent, canStoreBlobs, caseInsensitiveRegExpSQL, createTableOptionsSql, createTableSql, createTableTypeQualifierSql, exceptionForUpdate, getConnection, getFixedPtSqlDefinition, getForeignKeyDefinition, getIndexLength, getJdbcMetadataName, getLongSqlDefinition, getPrimaryKeyDefinition, getQuotedName, getQuotedValue, getSchema, getSqlDefaultValue, getSqlDefinition, givesCapabilitySQL, melatiName, selectLimit, shutdown, sqlBooleanValueOfRaw, tableInitialisationSql, toString, unloadDriver, unreservedName

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Postgresql

public Postgresql()

Constructor.

Method Detail

canDropColumns

public boolean canDropColumns()

Whether this DBMS can drop columns. Postgresql has been able to since 7.4

Specified by:

canDropColumns in interface Dbms

Overrides:

canDropColumns in class AnsiStandard

Returns:

true if we can

preparedStatementPlaceholder

public String preparedStatementPlaceholder(PoemType<?> type)

Accommodate casting in placeholders.

Specified by:

preparedStatementPlaceholder in interface Dbms

Overrides:

preparedStatementPlaceholder in class AnsiStandard

Parameters:

type - the type to cast

Returns:

the place holder string

See Also:

Postgresql

getStringSqlDefinition

public String getStringSqlDefinition(int size)
                              throws SQLException

Accommodate String/Text distinction.

Specified by:

getStringSqlDefinition in interface Dbms

Overrides:

getStringSqlDefinition in class AnsiStandard

Parameters:

size - the string length (-1 means no limit)

Returns:

the SQL definition for a string of this size

Throws:

SQLException

See Also:

AnsiStandard.getStringSqlDefinition(int)

getBinarySqlDefinition

public String getBinarySqlDefinition(int size)
                              throws SQLException

Description copied from interface: Dbms

Accommodate different treatment of different sized binary data.

Specified by:

getBinarySqlDefinition in interface Dbms

Overrides:

getBinarySqlDefinition in class AnsiStandard

Parameters:

size - how big the field is

Returns:

the keyword to use

Throws:

SQLException

defaultPoemTypeOfColumnMetaData

public SQLPoemType<?> defaultPoemTypeOfColumnMetaData(ResultSet md)
                                               throws SQLException

An Object Id PoemType.

Specified by:

defaultPoemTypeOfColumnMetaData in interface Dbms

Overrides:

defaultPoemTypeOfColumnMetaData in class AnsiStandard

Parameters:

md - the JDBC metadata

Returns:

the PoemType to use

Throws:

SQLException - potentially

exceptionForUpdate

public SQLPoemException exceptionForUpdate(Table<?> table,
                                           String sql,
                                           boolean insert,
                                           SQLException e)

Description copied from interface: Dbms

An exception appropriate for expressing what really went wrong during a write to the db. This gives the opportunity to try to interpret the getMessage text returned by the underlying driver, so that a more friendly error page can be put together for the user. Canonically, this is used to separate out "duplicate key" errors from more serious problems.

Specified by:

exceptionForUpdate in interface Dbms

Overrides:

exceptionForUpdate in class AnsiStandard

Parameters:

table - The table on which the update was affected

sql - The operation attempted, or possibly null

insert - Whether the operation was an INSERT as opposed to an UPDATE

e - The raw SQL exception: the routine is meant to try to interpret e.getMessage if it can

Returns:

an appropriate exception

See Also:

exceptionForUpdate(org.melati.poem.Table<?>, java.lang.String, boolean, java.sql.SQLException)