QgsSQLStatement class

Class for parsing SQL statements.

Reference

Public types

class Node: Abstract node class.
class NodeBetweenOperator: 'X BETWEEN y and z' operator
class NodeBinaryOperator: Binary logical/arithmetical operator (AND, OR, =, +, ...)
class NodeCast: CAST operator.
class NodeColumnRef: Reference to a column.
class NodeColumnSorted: Column in a ORDER BY.
class NodeFunction: Function with a name and arguments node.
class NodeInOperator: 'x IN (y, z)' operator
class NodeJoin: Join definition.
class NodeList: A list of nodes.
class NodeLiteral: Literal value (integer, integer64, double, string)
class NodeSelect: SELECT node.
class NodeSelectedColumn: Selected column.
class NodeTableDef: Table definition.
class NodeUnaryOperator: Unary logicial/arithmetical operator ( NOT, - )
class RecursiveVisitor: A visitor that recursively explores all children.
class Visitor: Support for visitor pattern - algorithms dealing with the statement may be implemented without modifying the Node classes.
enum BinaryOperator { boOr, boAnd, boEQ, boNE, boLE, boGE, boLT, boGT, boLike, boNotLike, boILike, boNotILike, boIs, boIsNot, boPlus, boMinus, boMul, boDiv, boIntDiv, boMod, boPow, boConcat }: list of binary operators
enum JoinType { jtDefault, jtLeft, jtLeftOuter, jtRight, jtRightOuter, jtCross, jtInner, jtFull }: list of join types
enum NodeType { ntUnaryOperator, ntBinaryOperator, ntInOperator, ntBetweenOperator, ntFunction, ntLiteral, ntColumnRef, ntSelectedColumn, ntSelect, ntTableDef, ntJoin, ntColumnSorted, ntCast }: Node type.
enum UnaryOperator { uoNot, uoMinus }: list of unary operators

Public static variables

static const char* BINARY_OPERATOR_TEXT
static const char* JOIN_TYPE_TEXT
static const char* UNARY_OPERATOR_TEXT

Public static functions

static auto quotedIdentifier(QString name) -> QString: Returns a quoted column reference (in double quotes)
static auto quotedIdentifierIfNeeded(const QString& name) -> QString: Returns a quoted column reference (in double quotes) if needed, or otherwise the original string.
static auto quotedString(QString text) -> QString: Returns a quoted version of a string (in single quotes)
static auto stripQuotedIdentifier(QString text) -> QString: Remove double quotes from an identifier.

Constructors, destructors, conversion operators

QgsSQLStatement(const QString& statement): Creates a new statement based on the provided string.
QgsSQLStatement(const QgsSQLStatement& other): Create a copy of this statement.

Public functions

void acceptVisitor(QgsSQLStatement::Visitor& v) const: Entry function for the visitor pattern.
auto doBasicValidationChecks(QString& errorMsgOut) const -> bool: Performs basic validity checks.
auto dump() const -> QString: Returns the statement string, constructed from the internal abstract syntax tree.
auto hasParserError() const -> bool: Returns true if an error occurred when parsing the input statement.
auto operator=(const QgsSQLStatement& other) -> QgsSQLStatement&: Create a copy of this statement.
auto parserErrorString() const -> QString: Returns parser error.
auto rootNode() const -> const QgsSQLStatement::Node*: Returns root node of the statement. Root node is null is parsing has failed.
auto statement() const -> QString: Returns the original, unmodified statement string.

Enum documentation

enum QgsSQLStatement::BinaryOperator

list of binary operators

enum QgsSQLStatement::JoinType

list of join types

enum QgsSQLStatement::UnaryOperator

list of unary operators

Function documentation

static QString QgsSQLStatement::quotedIdentifier(QString name)

Returns a quoted column reference (in double quotes)

static QString QgsSQLStatement::quotedIdentifierIfNeeded(const QString& name)

Returns a quoted column reference (in double quotes) if needed, or otherwise the original string.

static QString QgsSQLStatement::quotedString(QString text)

Returns a quoted version of a string (in single quotes)

static QString QgsSQLStatement::stripQuotedIdentifier(QString text)

Remove double quotes from an identifier.

bool QgsSQLStatement::doBasicValidationChecks(QString& errorMsgOut) const

Performs basic validity checks.

Basically checking that columns referencing a table, references a specified table. Returns true if the validation is successful

QString QgsSQLStatement::dump() const

Returns the statement string, constructed from the internal abstract syntax tree.

This does not contain any nice whitespace formatting or comments. In general it is preferable to use statement() instead.

QString QgsSQLStatement::statement() const

Returns the original, unmodified statement string.

If there was none supplied because it was constructed by sole API calls, dump() will be used to create one instead.