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RWDBSimpleCaseExpr Class Reference
SourcePro DB » DB Interface Module » Expressions

Used to build simple CASE expressions. More...

#include <rw/db/expr.h>

Inheritance diagram for RWDBSimpleCaseExpr:
RWDBExpr

Public Member Functions

 RWDBSimpleCaseExpr (const RWDBExpr &input)
 
 RWDBSimpleCaseExpr (const RWDBSimpleCaseExpr &simpleCaseExpr)
 
void else_ (const RWDBExpr &elseExpr)
 
RWDBSimpleCaseExpr & operator= (const RWDBSimpleCaseExpr &simpleCaseExpr)
 
void when (const RWDBExpr &whenExpr, const RWDBExpr &thenExpr)
 
- Public Member Functions inherited from RWDBExpr
 RWDBExpr ()
 
 RWDBExpr (const RWDBExpr &expr)
 
 RWDBExpr (char value)
 
 RWDBExpr (unsigned char value)
 
 RWDBExpr (short value)
 
 RWDBExpr (unsigned short value)
 
 RWDBExpr (int value)
 
 RWDBExpr (unsigned int value)
 
 RWDBExpr (long int value)
 
 RWDBExpr (unsigned long int value)
 
 RWDBExpr (long long value)
 
 RWDBExpr (unsigned long long value)
 
 RWDBExpr (float value)
 
 RWDBExpr (double value)
 
 RWDBExpr (long double value)
 
 RWDBExpr (const char *value)
 
 RWDBExpr (const wchar_t *value)
 
 RWDBExpr (const RWCString &value)
 
 RWDBExpr (const RWDecimalPortable &value)
 
 RWDBExpr (const RWDateTime &value)
 
 RWDBExpr (const RWDBDateTime &value)
 
 RWDBExpr (const RWDBDuration &value)
 
 RWDBExpr (const RWDate &value)
 
 RWDBExpr (const RWTime &value)
 
 RWDBExpr (const RWDBBlob &value)
 
 RWDBExpr (const RWBasicUString &value)
 
 RWDBExpr (const RWDBMBString &value)
 
 RWDBExpr (const RWWString &value)
 
 RWDBExpr (const RWDBValue &value, bool usePhraseBook=true)
 
 RWDBExpr (const RWDBColumn &column)
 
 RWDBExpr (const RWDBSelectorBase &subSelect)
 
 RWDBExpr (RWDBValueManip manip)
 
 RWDBExpr (const RWCollection &collection)
 
 RWDBExpr (const RWDBTable &)
 
 RWDBExpr (const RWDBColumn &left, const RWDBExpr &right)
 
 RWDBExpr (const RWDBColumn &left, const RWDBValue &right)
 
RWCString asString (const RWDBPhraseBook &phraseBook, AsStringControlFlag control=normal) const
 
RWDBCriterion between (const RWDBExpr &expression1, const RWDBExpr &expression2) const
 
RWDBCriterion in (const RWDBExpr &expression1) const
 
RWDBCriterion isNull (void) const
 
bool isValid (void) const
 
RWDBCriterion leftOuterJoin (const RWDBExpr &expression) const
 
RWDBCriterion like (const RWDBExpr &expression1) const
 
RWDBCriterion matchUnique (const RWDBExpr &expression1) const
 
RWDBExpr & operator= (const RWDBExpr &expr)
 
RWDBCriterion rightOuterJoin (const RWDBExpr &expression) const
 

Additional Inherited Members

- Public Types inherited from RWDBExpr
enum  AsStringControlFlag { normal, suppressTagsOnColumns, noPlaceHolder, placeHolderNotRecommended }
 
- Related Functions inherited from RWDBExpr
RWDBCriterion operator! (const RWDBCriterion &)
 
RWDBCriterion operator!= (const RWDBExpr &, const RWDBExpr &)
 
RWDBExpr operator% (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator&& (const RWDBCriterion &, const RWDBCriterion &)
 
RWDBExpr operator* (const RWDBExpr &, const RWDBExpr &)
 
RWDBExpr operator+ (const RWDBExpr &, const RWDBExpr &)
 
RWDBExpr operator+ (const RWDBExpr &)
 
RWDBExpr operator- (const RWDBExpr &, const RWDBExpr &)
 
RWDBExpr operator- (const RWDBExpr &)
 
RWDBExpr operator/ (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator< (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator<= (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator== (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator> (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator>= (const RWDBExpr &, const RWDBExpr &)
 
RWDBCriterion operator|| (const RWDBCriterion &, const RWDBCriterion &)
 
RWDBExpr rwdbAvg (const RWDBExpr &expr)
 
RWDBExpr rwdbCast (const RWDBExpr &expr, const RWDBValue &type)
 
RWDBExpr rwdbCast (const RWDBExpr &expr, const RWDBValue &typeName, const RWDBExpr &formatString)
 
RWDBExpr rwdbCast (const RWDBExpr &expr, const RWDBValue &typeName, const RWDBExpr &formatString, const RWDBExpr &secondaryFormat)
 
RWDBExpr rwdbCharLength (const RWDBExpr &expr)
 
RWDBExpr rwdbCount (const RWDBExpr &expr)
 
RWDBExpr rwdbCount ()
 
RWDBExpr rwdbCountDistinct (const RWDBExpr &expr)
 
RWDBExpr rwdbCurrentUser ()
 
RWDBCriterion rwdbExists (const RWDBSelectorBase &select)
 
RWDBExpr rwdbLower (const RWDBExpr &expr)
 
RWDBExpr rwdbMax (const RWDBExpr &expr)
 
RWDBExpr rwdbMin (const RWDBExpr &expr)
 
RWDBExpr rwdbName (const RWCString &name, const RWDBExpr &expr)
 
RWDBExpr rwdbPosition (const RWDBExpr &expr1, const RWDBExpr &expr2)
 
RWDBExpr rwdbSessionUser ()
 
RWDBExpr rwdbSubString (const RWDBExpr &expr1, const RWDBExpr &expr2)
 
RWDBExpr rwdbSubString (const RWDBExpr &expr1, const RWDBExpr &expr2, const RWDBExpr &expr3)
 
RWDBExpr rwdbSum (const RWDBExpr &expr)
 
RWDBExpr rwdbSystemDateTime ()
 
RWDBExpr rwdbSystemUser ()
 
RWDBExpr rwdbTrimBoth (const RWDBExpr &expr1, const RWDBExpr &expr2)
 
RWDBExpr rwdbTrimLeading (const RWDBExpr &expr1, const RWDBExpr &expr2)
 
RWDBExpr rwdbTrimTrailing (const RWDBExpr &expr1, const RWDBExpr &expr2)
 
RWDBExpr rwdbUpper (const RWDBExpr &expr)
 

Detailed Description

RWDBSimpleCaseExpr represents a specialized type of RWDBExpr used to specify a simple SQL CASE expression.

Synopsis
#include <rw/db/expr.h>
RWDBSimpleCaseExpr caseExpr(aDatabase.table("table1").column("column1"));
See also
RWDBSimpleCaseExpr is a special case of RWDBExpr. See RWDBExpr for more details.
Example
In this example, an RWDBSimpleCaseExpr is constructed with an input expression. The instance adds several WHEN expressions and an ELSE expression, then is finally inserted into the SELECT list.
// SELECT c1,
// (CASE c2 WHEN 'NameA' THEN c1 * 2 WHEN 'NameB' THEN c1 * 5 ELSE c1 * 10 END)
// FROM table1
// ORDER BY c2
// Instantiate a table object to represent the table.
RWDBTable t1 = aDatabase.table("table1");
// Instantiate a column object to represent the first column.
RWDBColumn c1 = t1["c1"];
// Instantiate a column object to represent the second column.
RWDBColumn c2 = t1["c2"];
// Instantiate simple CASE expression specifying column 2 as the input
// expression to be evaluated.
RWDBSimpleCaseExpr caseExpr(c2);
// Add WHEN clauses that are evaluated if column2 is equal to the
// specified WHEN expression argument.
caseExpr.when("NameA", RWDBExpr(c1) * 2);
caseExpr.when("NameB", RWDBExpr(c1) * 5);
// Add an ELSE expression that is evaluated if all WHEN clauses
// do not match.
caseExpr.elseExpr(c1 * 10);
// Instantiate a selector to represent a CASE query.
RWDBSelector aSel = db.selector();
// Add column 1 and the CASE expression to the SELECT list.
aSel << c1 << caseExpr;
// Specify an ORDER BY clause to order on column 2.
aSel.orderBy(c2);

Constructor & Destructor Documentation

RWDBSimpleCaseExpr::RWDBSimpleCaseExpr ( const RWDBExpr &  input)

Constructs an RWDBSimpleCaseExpr from input expression.

RWDBSimpleCaseExpr::RWDBSimpleCaseExpr ( const RWDBSimpleCaseExpr &  simpleCaseExpr)

Copy constructor. The created RWDBSimpleCaseExpr shares an implementation with simpleCaseExpr.

Member Function Documentation

void RWDBSimpleCaseExpr::else_ ( const RWDBExpr &  elseExpr)

Specifies the ELSE expression for self as elseExpr. If self already has an ELSE clause, this method replaces it.

RWDBSimpleCaseExpr& RWDBSimpleCaseExpr::operator= ( const RWDBSimpleCaseExpr &  simpleCaseExpr)

Assignment operator. Self shares an implementation with simpleCaseExpr. Returns a reference to self.

void RWDBSimpleCaseExpr::when ( const RWDBExpr &  whenExpr,
const RWDBExpr &  thenExpr 
)

Appends a WHEN/THEN clause to self where the argument whenExpr encapsulates the WHEN comparison expression, and the argument thenExpr encapsulates the THEN return expression.

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