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Slightly better error handling in constructor of postgres provider
git-svn-id: http://svn.osgeo.org/qgis/trunk@6892 c8812cc2-4d05-0410-92ff-de0c093fc19c
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wonder committed Apr 17, 2007
1 parent 0dc4a3b commit a4cf54ada9cf4d1c3e8deb2b6de6fe98463e8596
Showing with 164 additions and 163 deletions.
  1. +164 −163 src/providers/postgres/qgspostgresprovider.cpp
@@ -112,186 +112,187 @@ QgsPostgresProvider::QgsPostgresProvider(QString const & uri)

PGconn *pd = PQconnectdb((const char *) mUri.connInfo);
// check the connection status
if (PQstatus(pd) == CONNECTION_OK)
if (PQstatus(pd) != CONNECTION_OK)
{
// store the connection for future use
connection = pd;
QgsDebugMsg("Connection to database failed");
valid = false;
return;
}

// store the connection for future use
connection = pd;

//set client encoding to unicode because QString uses UTF-8 anyway
QgsDebugMsg("setting client encoding to UNICODE");
int errcode=PQsetClientEncoding(connection, "UNICODE");
if(errcode==0) {
QgsDebugMsg("encoding successfully set");
} else if(errcode==-1) {
QgsDebugMsg("error in setting encoding");
} else {
QgsDebugMsg("undefined return value from encoding setting");
}
//set client encoding to unicode because QString uses UTF-8 anyway
QgsDebugMsg("setting client encoding to UNICODE");

int errcode=PQsetClientEncoding(connection, "UNICODE");

if(errcode==0) {
QgsDebugMsg("encoding successfully set");
} else if(errcode==-1) {
QgsDebugMsg("error in setting encoding");
} else {
QgsDebugMsg("undefined return value from encoding setting");
}

QgsDebugMsg("Checking for select permission on the relation\n");

// Check that we can read from the table (i.e., we have
// select permission).
QString sql = "select * from " + mSchemaTableName + " limit 1";
PGresult* testAccess = PQexec(pd, (const char*)(sql.utf8()));
if (PQresultStatus(testAccess) != PGRES_TUPLES_OK)
{
showMessageBox(tr("Unable to access relation"),
tr("Unable to access the ") + mSchemaTableName +
tr(" relation.\nThe error message from the database was:\n") +
QString(PQresultErrorMessage(testAccess)) + ".\n" +
"SQL: " + sql);
PQclear(testAccess);
valid = false;
return;
}
QgsDebugMsg("Checking for select permission on the relation\n");

// Check that we can read from the table (i.e., we have
// select permission).
QString sql = "select * from " + mSchemaTableName + " limit 1";
PGresult* testAccess = PQexec(pd, (const char*)(sql.utf8()));
if (PQresultStatus(testAccess) != PGRES_TUPLES_OK)
{
showMessageBox(tr("Unable to access relation"),
tr("Unable to access the ") + mSchemaTableName +
tr(" relation.\nThe error message from the database was:\n") +
QString(PQresultErrorMessage(testAccess)) + ".\n" +
"SQL: " + sql);
PQclear(testAccess);
valid = false;
PQfinish(connection);
return;
}
PQclear(testAccess);

/* Check to see if we have GEOS support and if not, warn the user about
the problems they will see :) */
QgsDebugMsg("Checking for GEOS support");
/* Check to see if we have GEOS support and if not, warn the user about
the problems they will see :) */
QgsDebugMsg("Checking for GEOS support");

if(!hasGEOS(pd))
{
showMessageBox(tr("No GEOS Support!"),
tr("Your PostGIS installation has no GEOS support.\n"
"Feature selection and identification will not "
"work properly.\nPlease install PostGIS with "
"GEOS support (http://geos.refractions.net)"));
}
//--std::cout << "Connection to the database was successful\n";
if(!hasGEOS(pd))
{
showMessageBox(tr("No GEOS Support!"),
tr("Your PostGIS installation has no GEOS support.\n"
"Feature selection and identification will not "
"work properly.\nPlease install PostGIS with "
"GEOS support (http://geos.refractions.net)"));
}
//--std::cout << "Connection to the database was successful\n";

if (getGeometryDetails()) // gets srid and geometry type
if (!getGeometryDetails()) // gets srid and geometry type
{
// the table is not a geometry table
numberFeatures = 0;
valid = false;

QgsDebugMsg("Invalid Postgres layer");
PQfinish(connection);
return;
}

deduceEndian();
calculateExtents();
getFeatureCount();

// Get the relation oid for use in later queries
sql = "SELECT oid FROM pg_class WHERE relname = '" + mTableName + "' AND relnamespace = ("
"SELECT oid FROM pg_namespace WHERE nspname = '" + mSchemaName + "')";
PGresult *tresult= PQexec(pd, (const char *)(sql.utf8()));
QString tableoid = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

// Get the table description
sql = "SELECT description FROM pg_description WHERE "
"objoid = " + tableoid + " AND objsubid = 0";
tresult = PQexec(pd, (const char*) sql.utf8());
if (PQntuples(tresult) > 0)
mDataComment = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

// Populate the field vector for this layer. The field vector contains
// field name, type, length, and precision (if numeric)
sql = "select * from " + mSchemaTableName + " limit 0";

PGresult *result = PQexec(pd, (const char *) (sql.utf8()));
//--std::cout << "Field: Name, Type, Size, Modifier:" << std::endl;

// The queries inside this loop could possibly be combined into one
// single query - this would make the code run faster.

for (int i = 0; i < PQnfields(result); i++)
{
QString fieldName = PQfname(result, i);
int fldtyp = PQftype(result, i);
QString typOid = QString().setNum(fldtyp);
int fieldModifier = PQfmod(result, i);
QString fieldComment("");

sql = "SELECT typname, typlen FROM pg_type WHERE "
"oid = (SELECT typelem FROM pg_type WHERE "
"typelem = " + typOid + " AND typlen = -1)";

PGresult* oidResult = PQexec(pd, (const char *) sql);
QString fieldTypeName = PQgetvalue(oidResult, 0, 0);
QString fieldSize = PQgetvalue(oidResult, 0, 1);
PQclear(oidResult);

sql = "SELECT attnum FROM pg_attribute WHERE "
"attrelid = " + tableoid + " AND attname = '" + fieldName + "'";
PGresult *tresult = PQexec(pd, (const char *)(sql.utf8()));
QString attnum = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

sql = "SELECT description FROM pg_description WHERE "
"objoid = " + tableoid + " AND objsubid = " + attnum;
tresult = PQexec(pd, (const char*)(sql.utf8()));
if (PQntuples(tresult) > 0)
fieldComment = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

QgsDebugMsg("Field: " + attnum + " maps to " + QString::number(i) + " " + fieldName + ", "
+ fieldTypeName + " (" + QString::number(fldtyp) + "), " + fieldSize + ", " + QString::number(fieldModifier));

attributeFieldsIdMap[attnum.toInt()] = i;

if(fieldName!=geometryColumn)
{
deduceEndian();
calculateExtents();
getFeatureCount();

// Get the relation oid for use in later queries
sql = "SELECT oid FROM pg_class WHERE relname = '" + mTableName + "' AND relnamespace = ("
"SELECT oid FROM pg_namespace WHERE nspname = '" + mSchemaName + "')";
PGresult *tresult= PQexec(pd, (const char *)(sql.utf8()));
QString tableoid = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

// Get the table description
sql = "SELECT description FROM pg_description WHERE "
"objoid = " + tableoid + " AND objsubid = 0";
tresult = PQexec(pd, (const char*) sql.utf8());
if (PQntuples(tresult) > 0)
mDataComment = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

// Populate the field vector for this layer. The field vector contains
// field name, type, length, and precision (if numeric)
sql = "select * from " + mSchemaTableName + " limit 0";

PGresult *result = PQexec(pd, (const char *) (sql.utf8()));
//--std::cout << "Field: Name, Type, Size, Modifier:" << std::endl;

// The queries inside this loop could possibly be combined into one
// single query - this would make the code run faster.

for (int i = 0; i < PQnfields(result); i++)
{
QString fieldName = PQfname(result, i);
int fldtyp = PQftype(result, i);
QString typOid = QString().setNum(fldtyp);
int fieldModifier = PQfmod(result, i);
QString fieldComment("");

sql = "SELECT typname, typlen FROM pg_type WHERE "
"oid = (SELECT typelem FROM pg_type WHERE "
"typelem = " + typOid + " AND typlen = -1)";

PGresult* oidResult = PQexec(pd, (const char *) sql);
QString fieldTypeName = PQgetvalue(oidResult, 0, 0);
QString fieldSize = PQgetvalue(oidResult, 0, 1);
PQclear(oidResult);

sql = "SELECT attnum FROM pg_attribute WHERE "
"attrelid = " + tableoid + " AND attname = '" + fieldName + "'";
PGresult *tresult = PQexec(pd, (const char *)(sql.utf8()));
QString attnum = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

sql = "SELECT description FROM pg_description WHERE "
"objoid = " + tableoid + " AND objsubid = " + attnum;
tresult = PQexec(pd, (const char*)(sql.utf8()));
if (PQntuples(tresult) > 0)
fieldComment = PQgetvalue(tresult, 0, 0);
PQclear(tresult);

QgsDebugMsg("Field: " + attnum + " maps to " + QString::number(i) + " " + fieldName + ", "
+ fieldTypeName + " (" + QString::number(fldtyp) + "), " + fieldSize + ", " + QString::number(fieldModifier));

attributeFieldsIdMap[attnum.toInt()] = i;
QVariant::Type fieldType;
if (fieldTypeName.find("int") != -1 || fieldTypeName.find("serial") != -1)
fieldType = QVariant::Int;
else if (fieldTypeName == "real" || fieldTypeName == "double precision" || \
fieldTypeName.find("float") != -1)
fieldType = QVariant::Double;
else
fieldType = QVariant::String;
attributeFields.insert(i, QgsField(fieldName, fieldType, fieldTypeName, fieldSize.toInt(), fieldModifier, fieldComment));
}
}
PQclear(result);

if(fieldName!=geometryColumn)
{
QVariant::Type fieldType;
if (fieldTypeName.find("int") != -1 || fieldTypeName.find("serial") != -1)
fieldType = QVariant::Int;
else if (fieldTypeName == "real" || fieldTypeName == "double precision" || \
fieldTypeName.find("float") != -1)
fieldType = QVariant::Double;
else
fieldType = QVariant::String;
attributeFields.insert(i, QgsField(fieldName, fieldType, fieldTypeName, fieldSize.toInt(), fieldModifier, fieldComment));
}
}
PQclear(result);
// set the primary key
getPrimaryKey();

// set the primary key
getPrimaryKey();

// Set the postgresql message level so that we don't get the
// 'there is no transaction in progress' warning.
// Set the postgresql message level so that we don't get the
// 'there is no transaction in progress' warning.
#ifndef QGISDEBUG
PQexec(connection, "set client_min_messages to error");
PQexec(connection, "set client_min_messages to error");
#endif

// Kick off the long running threads
// Kick off the long running threads

#ifdef POSTGRESQL_THREADS
QgsDebugMsg("About to touch mExtentThread");
mExtentThread.setConnInfo( mUri.connInfo );
mExtentThread.setTableName( mTableName );
mExtentThread.setSqlWhereClause( sqlWhereClause );
mExtentThread.setGeometryColumn( geometryColumn );
mExtentThread.setCallback( this );
QgsDebugMsg("About to start mExtentThread");
mExtentThread.start();
QgsDebugMsg("Main thread just dispatched mExtentThread");

QgsDebugMsg("About to touch mCountThread");
mCountThread.setConnInfo( mUri.connInfo );
mCountThread.setTableName( mTableName );
mCountThread.setSqlWhereClause( sqlWhereClause );
mCountThread.setGeometryColumn( geometryColumn );
mCountThread.setCallback( this );
QgsDebugMsg("About to start mCountThread");
mCountThread.start();
QgsDebugMsg("Main thread just dispatched mCountThread");
QgsDebugMsg("About to touch mExtentThread");
mExtentThread.setConnInfo( mUri.connInfo );
mExtentThread.setTableName( mTableName );
mExtentThread.setSqlWhereClause( sqlWhereClause );
mExtentThread.setGeometryColumn( geometryColumn );
mExtentThread.setCallback( this );
QgsDebugMsg("About to start mExtentThread");
mExtentThread.start();
QgsDebugMsg("Main thread just dispatched mExtentThread");

QgsDebugMsg("About to touch mCountThread");
mCountThread.setConnInfo( mUri.connInfo );
mCountThread.setTableName( mTableName );
mCountThread.setSqlWhereClause( sqlWhereClause );
mCountThread.setGeometryColumn( geometryColumn );
mCountThread.setCallback( this );
QgsDebugMsg("About to start mCountThread");
mCountThread.start();
QgsDebugMsg("Main thread just dispatched mCountThread");
#endif
}
else
{
// the table is not a geometry table
numberFeatures = 0;
valid = false;

QgsDebugMsg("Invalid Postgres layer");
}

ready = false; // not ready to read yet cuz the cursor hasn't been created

} else {
valid = false;
//--std::cout << "Connection to database failed\n";
}
ready = false; // not ready to read yet cuz the cursor hasn't been created

//fill type names into sets
mSupportedNativeTypes.insert("double precision");

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