join two expressionList with "or" or "and"

ebean

Solution

You need to check out the Ebean Junctions feature.

There are two kinds of Junctions, Conjuction and Disjunction. With a conjunction you can join together many expressions with AND, and with a Disjunction you join together many expressions with OR.

For example:

Query q = Ebean.createQuery(YourClass.class);
q.where().disjunction()
    .add(Expr.eq("varName1",value).eq("varName2",value))
    .add(Expr.eq("varName3",value3))
    .add(Expr.eq("varName4",value4).eq("varName5",value5))

generate a sql like this:

SELECT * FROM tablename WHERE (varName1=value and varName2=value) or (varName3=value3) or (varName4=value4 and varName5=value5)

If you want the flexibility to select the type of junction you can do this:

Query q = Ebean.createQuery(YourClass.class);
Junction<YourClass> junction;

if("or".equals(desiredJunctionType)){
    junction = query.where().disjunction();
} else {
    junction = query.where().conjunction();
}

// then you can add your expressions:
junction.add(Expr.eq("varName1",value).eq("varName2",value));
junction.add(Expr.eq("varName3",value3));
// etc...
// and finaly get the query results
List<YourClass> yourResult = junction.query().findList();

Problem

I'm having some trouble to join 2 expressionList with an "or". This is an example of what I'm doing: ``` RelationGroup prg =... ExpressionList<User> exp = User.find.where(); List<ExpressionList<User>> expressions = new ArrayList<ExpressionList<User>>() List<String> relations = new ArrayList<String>() while(prg != null){ if(prg.prevGroupRelation != null) relations.add(prg.prevGroupRelation); for(RelationAtt pra : prg.prAtt){ if(pra.rel.equals("eq")) exp = exp.eq(pra.name, pra.value1 ); else if(pra.rel.equals("lt")) exp = exp.lt(pra.name, pra.value1); else if(pra.rel.equals("gt")) exp = exp.gt(pra.name, pra.value1); else if(pra.rel.equals("bw")) exp = exp.gt(pra.name, pra.value1).lt(pra.name, pra.value2); } expression.add(exp); prg=prg.nextPRG(); exp = new ExpressionList<User>(); } for(i=0;i<expressions.count-1; i++) if(relations[i].equals("or")){ //ToDo: (expressions[i]) or (expressions[i+1]) }else{ //ToDo: (expressions[i]) and (expressions[i+1]) } ``` I need to have something like: ``` select * from tableName where (varName1=value and varName2=value) or (varName3) or (varName4=value and varName5=value) ``` This is fully dynamic so the varNames can be any of the currently existing(because the queries are build by the user using a web page interface), so i can't use raw SQL that easily. Now i need to join prevExp and exp with an or/and and replace exp. The `ExpressionList.or(exp, exp)` receive 2 Expressions. Any help with this is appreciated thank you

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