drogon::orm::Criteria Class Reference

this class represents a comparison condition. More...

#include <drogon/orm/Criteria.h>

Public Member Functions
	operator bool () const
	Check if the condition is empty.
std::string	criteriaString () const
	return the condition string in SQL.
template<typename... Arguments>
	Criteria (const CustomSql &sql, Arguments &&...args)
	Construct a new custom Criteria object.
template<typename... Arguments>
	Criteria (CustomSql &&sql, Arguments &&...args)
template<typename T>
	Criteria (const std::string &colName, const CompareOperator &opera, T &&arg)
	Construct a new Criteria object.
template<typename T>
	Criteria (const std::string &colName, const CompareOperator &opera, const std::vector< T > &args)
template<typename T>
	Criteria (const std::string &colName, const CompareOperator &opera, std::vector< T > &&args)
template<typename T>
	Criteria (const std::string &colName, const CompareOperator &opera, std::vector< T > &args)
template<typename T>
	Criteria (const std::string &colName, T &&arg)
	Construct a new Criteria object presenting a equal expression.
	Criteria (const std::string &colName, const CompareOperator &opera)
	Construct a new Criteria object presenting a expression without parameters.
	Criteria (const std::string &colName, CompareOperator &opera)
	Criteria (const std::string &colName, CompareOperator &&opera)
	Criteria (const Json::Value &json) noexcept(false)
	Construct a new Criteria object.
void	outputArgs (internal::SqlBinder &binder) const
	Output arguments to the SQL binder object.

Friends
DROGON_EXPORT const Criteria	operator&& (Criteria cond1, Criteria cond2)
DROGON_EXPORT const Criteria	operator|| (Criteria cond1, Criteria cond2)

Detailed Description

this class represents a comparison condition.

Constructor & Destructor Documentation

Criteria() [1/5]

template<typename... Arguments>

drogon::orm::Criteria::Criteria ( const CustomSql & sql, Arguments &&... args )

inlineexplicit

Construct a new custom Criteria object.

Parameters

sql	The SQL statement to be executed.
args	The parameters to be passed to the placeholders.

Note

Use $? as placeholders in the SQL statement.

Be careful that the placeholders are not the same as the ones in functions such as drogon::orm::DbClient::execSqlAsync. Which means you couldn't use numeric placeholders such as $1, $2 to represent the order of the arguments.

The arguments should be in the same order as the placeholders.

Criteria() [2/5]

template<typename T>

drogon::orm::Criteria::Criteria ( const std::string & colName, const CompareOperator & opera, T && arg )

inline

Construct a new Criteria object.

Template Parameters

T	the type of the object to be compared with.

Parameters

colName	The name of the column.
opera	The type of the comparison.
arg	The object to be compared with.

Criteria() [3/5]

template<typename T>

drogon::orm::Criteria::Criteria ( const std::string & colName, T && arg )

inline

Construct a new Criteria object presenting a equal expression.

Template Parameters

T	The type of the object to be equal to.

Parameters

colName	The name of the column.
arg	The object to be equal to.

Criteria() [4/5]

drogon::orm::Criteria::Criteria ( const std::string & colName, const CompareOperator & opera )

inline

Construct a new Criteria object presenting a expression without parameters.

Parameters

colName	The name of the column.
opera	The type of the comparison. it must be one of the following: CompareOperator::IsNotNull CompareOperator::IsNull

Criteria() [5/5]

drogon::orm::Criteria::Criteria ( const Json::Value & json )

explicit

Construct a new Criteria object.

Parameters

json	A json object representing the criteria

Note

the json object must be a array of three items, the first is the name of the field, the second is the comparison operator and the third is the value to be compared. The valid operators are "=","<",">","<=",">=","!=","in" for example: ["id","=",1] means 'id = 1' ["id","!=",null] means 'id is not null' ["user_name","in",["Tom","Bob"]] means 'user_name in ('Tom', 'Bob')' ["price","<",1000] means 'price < 1000'

Member Function Documentation

criteriaString()

std::string drogon::orm::Criteria::criteriaString ( ) const

inline

return the condition string in SQL.

Returns

std::string

operator bool()

drogon::orm::Criteria::operator bool ( ) const

inlineexplicit

Check if the condition is empty.

Returns

true means the condition is not empty.

false means the condition is empty.

outputArgs()

void drogon::orm::Criteria::outputArgs ( internal::SqlBinder & binder ) const

inline

Output arguments to the SQL binder object.

Parameters

binder

The SQL binder object.

Note

This method must be called by drogon.

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

• orm_lib/inc/drogon/orm/Criteria.h