QSqlResult

The QSqlResult class provides an abstract interface for accessing data from specific SQL databases. More

Inheritance diagram of PySide2.QtSql.QSqlResult

Synopsis

Functions

Virtual functions

Detailed Description

Normally, you would use QSqlQuery instead of QSqlResult , since QSqlQuery provides a generic wrapper for database-specific implementations of QSqlResult .

If you are implementing your own SQL driver (by subclassing QSqlDriver ), you will need to provide your own QSqlResult subclass that implements all the pure virtual functions and other virtual functions that you need.

See also

QSqlDriver

class QSqlResult(db)
param db

QSqlDriver

Creates a QSqlResult using database driver db . The object is initialized to an inactive state.

See also

isActive() driver()

PySide2.QtSql.QSqlResult.BindingSyntax

This enum type specifies the different syntaxes for specifying placeholders in prepared queries.

Constant

Description

QSqlResult.PositionalBinding

Use the ODBC-style positional syntax, with “?” as placeholders.

QSqlResult.NamedBinding

Use the Oracle-style syntax with named placeholders (e.g., “:id”)

See also

bindingSyntax()

PySide2.QtSql.QSqlResult.addBindValue(val, type)
Parameters
  • val – object

  • typeParamType

Binds the value val of parameter type paramType to the next available position in the current record (row).

See also

bindValue()

PySide2.QtSql.QSqlResult.at()
Return type

int

Returns the current (zero-based) row position of the result. May return the special values BeforeFirstRow or AfterLastRow .

See also

setAt() isValid()

PySide2.QtSql.QSqlResult.bindValue(placeholder, val, type)
Parameters
  • placeholder – unicode

  • val – object

  • typeParamType

PySide2.QtSql.QSqlResult.bindValue(pos, val, type)
Parameters
  • posint

  • val – object

  • typeParamType

PySide2.QtSql.QSqlResult.bindValueType(placeholder)
Parameters

placeholder – unicode

Return type

ParamType

PySide2.QtSql.QSqlResult.bindValueType(pos)
Parameters

posint

Return type

ParamType

Returns the parameter type for the value bound at position index .

See also

boundValue()

PySide2.QtSql.QSqlResult.bindingSyntax()
Return type

BindingSyntax

Returns the binding syntax used by prepared queries.

PySide2.QtSql.QSqlResult.boundValue(placeholder)
Parameters

placeholder – unicode

Return type

object

PySide2.QtSql.QSqlResult.boundValue(pos)
Parameters

posint

Return type

object

Returns the value bound at position index in the current record (row).

PySide2.QtSql.QSqlResult.boundValueCount()
Return type

int

Returns the number of bound values in the result.

See also

boundValues()

PySide2.QtSql.QSqlResult.boundValueName(pos)
Parameters

posint

Return type

unicode

Returns the name of the bound value at position index in the current record (row).

See also

boundValue()

PySide2.QtSql.QSqlResult.boundValues()
Return type

Returns a vector of the result’s bound values for the current record (row).

PySide2.QtSql.QSqlResult.clear()

Clears the entire result set and releases any associated resources.

PySide2.QtSql.QSqlResult.data(i)
Parameters

iint

Return type

object

Returns the data for field index in the current row as a QVariant . This function is only called if the result is in an active state and is positioned on a valid record and index is non-negative. Derived classes must reimplement this function and return the value of field index , or QVariant() if it cannot be determined.

PySide2.QtSql.QSqlResult.detachFromResultSet()
PySide2.QtSql.QSqlResult.driver()
Return type

QSqlDriver

Returns the driver associated with the result. This is the object that was passed to the constructor.

PySide2.QtSql.QSqlResult.execBatch([arrayBind=false])
Parameters

arrayBindbool

Return type

bool

Executes a prepared query in batch mode if the driver supports it, otherwise emulates a batch execution using bindValue() and exec() . hasFeature() can be used to find out whether a driver supports batch execution.

Batch execution can be faster for large amounts of data since it reduces network roundtrips.

For batch executions, bound values have to be provided as lists of variants ( QVariantList ).

Each list must contain values of the same type. All lists must contain equal amount of values (rows).

NULL values are passed in as typed QVariants, for example QVariant(QVariant::Int) for an integer NULL value.

Example:

q = QSqlQuery()
q.prepare("insert into test (i1, i2, s) values (?, ?, ?)")

col1 = [1, 3]
col2 = [2, 4]
col3 = ["hello", "world"]

q.bindValue(0, col1)
q.bindValue(1, col2)
q.bindValue(2, col3)

if not q.execBatch():
    print q.lastError()

Here, we insert two rows into a SQL table, with each row containing three values.

See also

exec() hasFeature()

PySide2.QtSql.QSqlResult.exec_()
Return type

bool

Executes the query, returning true if successful; otherwise returns false.

See also

prepare()

PySide2.QtSql.QSqlResult.executedQuery()
Return type

unicode

Returns the query that was actually executed. This may differ from the query that was passed, for example if bound values were used with a prepared query and the underlying database doesn’t support prepared queries.

See also

exec() setQuery()

PySide2.QtSql.QSqlResult.fetch(i)
Parameters

iint

Return type

bool

Positions the result to an arbitrary (zero-based) row index .

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the row index , and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

PySide2.QtSql.QSqlResult.fetchFirst()
Return type

bool

Positions the result to the first record (row 0) in the result.

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the first record, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

See also

fetch() fetchLast()

PySide2.QtSql.QSqlResult.fetchLast()
Return type

bool

Positions the result to the last record (last row) in the result.

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the last record, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

PySide2.QtSql.QSqlResult.fetchNext()
Return type

bool

Positions the result to the next available record (row) in the result.

This function is only called if the result is in an active state. The default implementation calls fetch() with the next index. Derived classes can reimplement this function and position the result to the next record in some other way, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

PySide2.QtSql.QSqlResult.fetchPrevious()
Return type

bool

Positions the result to the previous record (row) in the result.

This function is only called if the result is in an active state. The default implementation calls fetch() with the previous index. Derived classes can reimplement this function and position the result to the next record in some other way, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

PySide2.QtSql.QSqlResult.handle()
Return type

object

Returns the low-level database handle for this result set wrapped in a QVariant or an invalid QVariant if there is no handle.

Warning

Use this with uttermost care and only if you know what you’re doing.

Warning

The handle returned here can become a stale pointer if the result is modified (for example, if you clear it).

Warning

The handle can be NULL if the result was not executed yet.

Warning

PostgreSQL: in forward-only mode, the handle of QSqlResult can change after calling fetch() , fetchFirst() , fetchLast() , fetchNext() , fetchPrevious() , .

The handle returned here is database-dependent, you should query the type name of the variant before accessing it.

This example retrieves the handle for a sqlite result:

query = QSqlQuery ...
v = query.result().handle()
if v.isValid() and (v.typeName() == "sqlite3_stmt*"):
    # v.data() returns a pointer to the handle
    handle = v.data()
    if handle != 0: # check that it is not NULL
        ...

This snippet returns the handle for PostgreSQL or MySQL:

if v.typeName() == "PGresult*":
    handle = v.data()
    if handle != 0 ...

if v.typeName() == "MYSQL_STMT*":
    handle = v.data()
    if handle != 0 ...
}

See also

handle()

PySide2.QtSql.QSqlResult.hasOutValues()
Return type

bool

Returns true if at least one of the query’s bound values is a QSql::Out or a InOut ; otherwise returns false .

See also

bindValueType()

PySide2.QtSql.QSqlResult.isActive()
Return type

bool

Returns true if the result has records to be retrieved; otherwise returns false .

PySide2.QtSql.QSqlResult.isForwardOnly()
Return type

bool

Returns true if you can only scroll forward through the result set; otherwise returns false .

See also

setForwardOnly()

PySide2.QtSql.QSqlResult.isNull(i)
Parameters

iint

Return type

bool

Returns true if the field at position index in the current row is null; otherwise returns false .

PySide2.QtSql.QSqlResult.isSelect()
Return type

bool

Returns true if the current result is from a SELECT statement; otherwise returns false .

See also

setSelect()

PySide2.QtSql.QSqlResult.isValid()
Return type

bool

Returns true if the result is positioned on a valid record (that is, the result is not positioned before the first or after the last record); otherwise returns false .

See also

at()

PySide2.QtSql.QSqlResult.lastError()
Return type

QSqlError

Returns the last error associated with the result.

See also

setLastError()

PySide2.QtSql.QSqlResult.lastInsertId()
Return type

object

Returns the object ID of the most recent inserted row if the database supports it. An invalid QVariant will be returned if the query did not insert any value or if the database does not report the id back. If more than one row was touched by the insert, the behavior is undefined.

Note that for Oracle databases the row’s ROWID will be returned, while for MySQL databases the row’s auto-increment field will be returned.

See also

hasFeature()

PySide2.QtSql.QSqlResult.lastQuery()
Return type

unicode

Returns the current SQL query text, or an empty string if there isn’t one.

See also

setQuery()

PySide2.QtSql.QSqlResult.nextResult()
Return type

bool

PySide2.QtSql.QSqlResult.numRowsAffected()
Return type

int

Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a SELECT statement.

See also

size()

PySide2.QtSql.QSqlResult.numericalPrecisionPolicy()
Return type

NumericalPrecisionPolicy

PySide2.QtSql.QSqlResult.prepare(query)
Parameters

query – unicode

Return type

bool

Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly. Returns true if the query is prepared successfully; otherwise returns false .

See also

exec()

PySide2.QtSql.QSqlResult.record()
Return type

QSqlRecord

Returns the current record if the query is active; otherwise returns an empty QSqlRecord .

The default implementation always returns an empty QSqlRecord .

See also

isActive()

PySide2.QtSql.QSqlResult.reset(sqlquery)
Parameters

sqlquery – unicode

Return type

bool

Sets the result to use the SQL statement query for subsequent data retrieval.

Derived classes must reimplement this function and apply the query to the database. This function is only called after the result is set to an inactive state and is positioned before the first record of the new result. Derived classes should return true if the query was successful and ready to be used, or false otherwise.

See also

setQuery()

PySide2.QtSql.QSqlResult.resetBindCount()

Resets the number of bind parameters.

PySide2.QtSql.QSqlResult.savePrepare(sqlquery)
Parameters

sqlquery – unicode

Return type

bool

Prepares the given query , using the underlying database functionality where possible. Returns true if the query is prepared successfully; otherwise returns false .

Note: This method should have been called “safePrepare()”.

See also

prepare()

PySide2.QtSql.QSqlResult.setActive(a)
Parameters

abool

This function is provided for derived classes to set the internal active state to active .

See also

isActive()

PySide2.QtSql.QSqlResult.setAt(at)
Parameters

atint

This function is provided for derived classes to set the internal (zero-based) row position to index .

See also

at()

PySide2.QtSql.QSqlResult.setForwardOnly(forward)
Parameters

forwardbool

Sets forward only mode to forward . If forward is true, only fetchNext() is allowed for navigating the results. Forward only mode needs much less memory since results do not have to be cached. By default, this feature is disabled.

Setting forward only to false is a suggestion to the database engine, which has the final say on whether a result set is forward only or scrollable. isForwardOnly() will always return the correct status of the result set.

Note

Calling after execution of the query will result in unexpected results at best, and crashes at worst.

Note

To make sure the forward-only query completed successfully, the application should check lastError() for an error not only after executing the query, but also after navigating the query results.

Warning

PostgreSQL: While navigating the query results in forward-only mode, do not execute any other SQL command on the same database connection. This will cause the query results to be lost.

PySide2.QtSql.QSqlResult.setLastError(e)
Parameters

eQSqlError

This function is provided for derived classes to set the last error to error .

See also

lastError()

PySide2.QtSql.QSqlResult.setNumericalPrecisionPolicy(policy)
Parameters

policyNumericalPrecisionPolicy

PySide2.QtSql.QSqlResult.setQuery(query)
Parameters

query – unicode

Sets the current query for the result to query . You must call reset() to execute the query on the database.

See also

reset() lastQuery()

PySide2.QtSql.QSqlResult.setSelect(s)
Parameters

sbool

This function is provided for derived classes to indicate whether or not the current statement is a SQL SELECT statement. The select parameter should be true if the statement is a SELECT statement; otherwise it should be false.

See also

isSelect()

PySide2.QtSql.QSqlResult.size()
Return type

int

Returns the size of the SELECT result, or -1 if it cannot be determined or if the query is not a SELECT statement.