QSqlResult

PyQt5.QtSql.QSqlResult

Description

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

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.

Enums

BindingSyntax

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

See also

bindingSyntax().

Member	Value	Description
NamedBinding	1	Use the Oracle-style syntax with named placeholders (e.g., “:id”)
PositionalBinding	0	Use the ODBC-style positional syntax, with “?” as placeholders.

Methods

__init__(QSqlDriver)

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

See also

isActive(), driver().

---

addBindValue(Any, Union[ParamType, ParamTypeFlag])

TODO

---

at() → int

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

See also

setAt(), isValid().

---

bindingSyntax() → BindingSyntax

Returns the binding syntax used by prepared queries.

---

bindValue(int, Any, Union[ParamType, ParamTypeFlag])

TODO

---

bindValue(str, Any, Union[ParamType, ParamTypeFlag])

TODO

---

bindValueType(str) → ParamType

This is an overloaded function.

Returns the parameter type for the value bound with the given placeholder name.

---

bindValueType(int) → ParamType

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

See also

boundValue().

---

boundValue(str) → Any

This is an overloaded function.

Returns the value bound by the given placeholder name in the current record (row).

See also

bindValueType().

---

boundValue(int) → Any

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

See also

bindValue(), boundValues().

---

boundValueCount() → int

Returns the number of bound values in the result.

See also

boundValues().

---

boundValueName(int) → str

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

See also

boundValue().

---

boundValues() → List[Any]

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

See also

boundValueCount().

---

clear()

Clears the entire result set and releases any associated resources.

---

data(int) → Any

TODO

---

driver() → QSqlDriver

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

---

exec() → bool

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

See also

prepare().

---

exec_() → bool

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

See also

prepare().

---

executedQuery() → str

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().

---

fetch(int) → bool

TODO

---

fetchFirst() → bool

TODO

---

fetchLast() → bool

TODO

---

fetchNext() → 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.

See also

fetch(), fetchPrevious().

---

fetchPrevious() → 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.

---

handle() → Any

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(), nextResult().

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:

# QSqlQuery query = ...
# QVariant v = query.result()->handle();
# if (v.isValid() && qstrcmp(v.typeName(), "sqlite3_stmt*") == 0) {
#     // v.data() returns a pointer to the handle
#     sqlite3_stmt *handle = *static_cast<sqlite3_stmt **>(v.data());
#     if (handle) {
#         ...
#     }
# }

This snippet returns the handle for PostgreSQL or MySQL:

# if (qstrcmp(v.typeName(), "PGresult*") == 0) {
#     PGresult *handle = *static_cast<PGresult **>(v.data());
#     if (handle) ...
# }

# if (qstrcmp(v.typeName(), "MYSQL_STMT*") == 0) {
#     MYSQL_STMT *handle = *static_cast<MYSQL_STMT **>(v.data());
#     if (handle) ...
# }

See also

handle().

---

hasOutValues() → bool

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

See also

bindValueType().

---

isActive() → bool

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

---

isForwardOnly() → bool

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

See also

setForwardOnly().

---

isNull(int) → bool

TODO

---

isSelect() → bool

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

See also

setSelect().

---

isValid() → 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().

---

lastError() → QSqlError

Returns the last error associated with the result.

See also

setLastError().

---

lastInsertId() → Any

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().

---

lastQuery() → str

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

See also

setQuery().

---

numRowsAffected() → int

TODO

---

prepare(str) → 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().

---

record() → 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().

---

reset(str) → bool

TODO

---

savePrepare(str) → 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().

---

setActive(bool)

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

See also

isActive().

---

setAt(int)

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

See also

at().

---

setForwardOnly(bool)

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.

See also

isForwardOnly(), fetchNext(), setForwardOnly().

---

setLastError(QSqlError)

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

See also

lastError().

---

setQuery(str)

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

See also

reset(), lastQuery().

---

setSelect(bool)

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().

---

size() → int

TODO