sql Class Reference

class to manage all database interactions More...

#include <sql.h>

Collaboration diagram for sql:

[legend]List of all members.

Public Member Functions
void	setCursor ()
	Method to store the result of a query for later retrieval.
void	restoreCursor ()
	Method to retrieve a previously stored query result.
void	initConn (const QString &uName, const QString &dbName="guest", const QString &password="", const QString &connName="guestConn", const QString &host="localhost", const QString &connType="QPSQL")
int	prepare (const QString &functionName, int paramCnt, const QString &connName="")
int	prepare (const QString &command, const QString &connName="")
	Method used to prepare a SQL command.
void	bind (int posn, QVariant value, int qID=-1)
bool	query (int qID=-1)
bool	first ()
	Method to get the first result from the current query.
bool	next ()
	Method to get the next result from the current query.
bool	last ()
	Method to get the last result from the current query.
QVariant	get (int index)
QVariant	getFirst (int index)
QVariant	getNext (int index)
void	dump ()
	Method to dump out some details about the current result set.
QString *	useModuleConn ()
Static Public Member Functions
static sql *	Instance ()
	Method to get the singleton instance.
Static Public Attributes
static QString *	DefaultConnectionName = new QString("guestConn")
	The name of the default connection.

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Detailed Description

class to manage all database interactions

This is a singleton class that will manage the connections with the database. It will support any number of databases by using the QDatabase class.
All interactions with the database should be done with the instance of this class. If there is an error then an exception will be thrown, this can then be managed in the appropriate way.
If a cursor needs to be set within the scanning of a database then this is supported, however it is up to the developer to use these responsibly. That is they must be set and then restored in pairs.

Definition at line 39 of file sql.h.

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Member Function Documentation

void sql::bind (  int  posn, QVariant  value, int  qID = -1 )

Method used to bind values to a prepared query Warning: This method has a side effect of updating the activeQuery if qID is a valid index in queryList Parameters: posn  An index to the argument to be bound to value  The value of the argument to be set qID  The index of the prepared query to use Definition at line 110 of file sql.cpp. Referenced by ModLecAlloc::bindPKey(), DataClass::bindPKey(), TimeSlot::bindValues(), Staff::bindValues(), Room::bindValues(), Programme::bindValues(), Module::bindValues(), ModLecAlloc::bindValues(), Institute::bindValues(), Faculty::bindValues(), Department::bindValues(), TimeSlot::remove(), Programme::uniqueAbbrev(), Institute::uniqueAbbrev(), Faculty::uniqueAbbrev(), Department::uniqueAbbrev(), Room::uniqueCode(), Programme::uniqueName(), Module::uniqueName(), Institute::uniqueName(), Faculty::uniqueName(), Department::uniqueName(), Module::uniqueNomenclature(), ModLecAlloc::updateClassSizeonDB(), ModLecAlloc::updateGroupsonDB(), ModLecAlloc::updateLabGroupsonDB(), and ModLecAlloc::updateLabHoursonDB(). { if (qID >= 0 && qID < queryList.size()) { activeQuery = queryList.at(qID); } activeQuery->bindValue(posn, value); }

QVariant sql::get (  int  index  )

Method to get the value indicated by index from the current record Parameters: index  The index of result column to use Definition at line 158 of file sql.cpp. Referenced by getFirst(), and getNext(). { if (result == 0) throw sqlE(QSqlDatabase::database(lastDBConnName)); return result->value(index); }

QVariant sql::getFirst (  int  index  )

Method to position the record on the first record and get the value indicated by index Parameters: index  The index of result column to use Definition at line 165 of file sql.cpp. References first(), and get(). Referenced by DataClass::insert(), ModLecAlloc::ModLecAlloc(), TimeSlot::remove(), DataClass::remove(), DataClass::unique(), DataClass::update(), ModLecAlloc::updateClassSizeonDB(), ModLecAlloc::updateGroupsonDB(), ModLecAlloc::updateLabGroupsonDB(), and ModLecAlloc::updateLabHoursonDB(). { first(); return get(index); }

QVariant sql::getNext (  int  index  )

Method to get the value from the current record and move to the next result Parameters: index  The index of result column to use Definition at line 171 of file sql.cpp. References get(), and next(). { next(); return get(index); }

void sql::initConn (  const QString &  uName, const QString &  dbName = "guest", const QString &  password = "", const QString &  connName = "guestConn", const QString &  host = "localhost", const QString &  connType = "QPSQL" )

Method to create a connection to a database Warning: This method has a side effect for changing the value of lastDBConnName Parameters: uName  the name of database user dbName  the name of the database password  the users password to access the database connName  the name that will be used for the connection host  the name of the server where the database is hosted connType  the type of database, so the appropriate driver can be selected Definition at line 44 of file sql.cpp. { QSqlDatabase dbConn = QSqlDatabase::addDatabase(connType,connName); dbConn.setDatabaseName(dbName); dbConn.setUserName(uName); dbConn.setPassword(password); dbConn.setHostName(host); if (!dbConn.open()) { throw sqlE(dbConn, "Failed to log on to the Database"); } lastDBConnName = connName; }

int sql::prepare (  const QString &  functionName, int  paramCnt, const QString &  connName = "" )

Method used to prepare a SQL function with the number of parameter given Warning: This method has a side effect of updating the lstDBConnName if connName is provided This method has a side effect of updating the activeQuery Parameters: functionName  the name of the SQL function that is being prepared paramCnt  the number of parameters the function requires connName  the name of the database connection to be used if this is blank then lastDBConnName will be used Returns: An index to the query stored in the queryList Definition at line 66 of file sql.cpp. Referenced by TimeSlot::PrepareSQL(), Staff::PrepareSQL(), Room::PrepareSQL(), Programme::PrepareSQL(), Module::PrepareSQL(), ModLecAlloc::PrepareSQL(), Institute::PrepareSQL(), Faculty::PrepareSQL(), and Department::PrepareSQL(). { QString paramList = "?"; for (int cnt = 1; cnt < paramCnt; cnt++) { paramList += ", ?"; } QString command = "SELECT " + functionName + "(" + paramList + ")"; QString dbConn; if (connName=="") dbConn = lastDBConnName; else { dbConn = connName; lastDBConnName = dbConn; } QSqlQuery * preparedStmt = new QSqlQuery (QSqlDatabase::database(dbConn)); preparedStmt->prepare(command); queryList.append(preparedStmt); activeQuery = preparedStmt; return queryList.size()-1; }

bool sql::query (  int  qID = -1  )

Method to execute a query Warning: This method has a side effect of creating a new query and storing it in result. Any old query in result will be lost unless it it set as a cursor. Parameters: qID  The index of the prepared query to use See also: setCursor and restoreCursor Definition at line 121 of file sql.cpp. Referenced by DataClass::insert(), ModLecAlloc::ModLecAlloc(), TimeSlot::remove(), DataClass::remove(), DataClass::unique(), DataClass::update(), ModLecAlloc::updateClassSizeonDB(), ModLecAlloc::updateGroupsonDB(), ModLecAlloc::updateLabGroupsonDB(), and ModLecAlloc::updateLabHoursonDB(). { if (qID >= 0 && qID < queryList.size()) { activeQuery = queryList.at(qID); } result = new QSqlQuery(*activeQuery); bool success = result->exec(); if (success == false) throw sqlE(QSqlDatabase::database(lastDBConnName), "Query Error: \"" + result->lastQuery() +"\""); return success; }

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The documentation for this class was generated from the following files:

• Persistence/sql.h
• Persistence/sql.cpp

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