HowToSqlConditionLib.adoc added

others/guide/HowToSqlConditionLib.adoc

-How to use the SqlCondition
-===========================
+How to use the SqlCondition (state: 06.12.2018)
+===============================================
 :toc2: left
 :numbered:
 
@@ -72,6 +72,9 @@ The field name needs to be given with
 
 Or if you use only COLUMNNAME, you have to provide the fieldType.
 
+But keep in mind: Other than the original adito db. functions this lib caches the field types automatically (for the livetime of an SqlCondition Object).
+So most times it is save to use the first method. Even in loops or if you use the same Column several times.
+
 [source,javascript]
 ----
 myDescriptiveNameOfTheCondition.orPrepared("PERS.FIRSTNAME", 'Bob', "#<?");
@@ -136,4 +139,47 @@ Same as build and adds a string before and after the condition.
 [source,javascript]
 ----
 var myPreparedStatementArray = myDescriptiveNameOfTheCondition.buildSelect("select * from PERS", "1=0", "order by FIRSTNAME");
-----
\ No newline at end of file
+----
+
+== real world example ==
+Some examples, how this lib can be used.
+
+[source,javascript]
+----
+var productPriceData = (db.ROW, db.array(SqlCondition.begin()
+                    .andPrepare("PRODUCTPRICE.BUYSELL", buySell)
+                    .andPrepare("PRODUCTPRICE.PRODUCT_ID", pid)
+                    .andPrepare("PRODUCTPRICE.VALID_FROM", today, "# <= ?")
+                    .andSqlCondition(SqlCondition.begin()
+                        .orPrepare("PRODUCTPRICE.VALID_TO", today, "# >= ?")
+                        .or("PRODUCTPRICE.VALID_TO is null"), "1 = 2");
+                    .buildSelect("select PRICE, CURRENCY from PRODUCTPRICE", "1 = 2", "order by VALID_FROM desc")));
+----
+
+With a loop:
+[source,javascript]
+----
+function _getClassificationCondition(include) 
+{
+    var resultingCondition = new SqlCondition();
+    resultingCondition.andPrepare("SALESPROJECT_CLASSIFICATION.SALESPROJECT_ID", salesprojectId)
+        .andPrepare("SALESPROJECT_CLASSIFICATION.CLASS", classId);
+
+    var typeCondition = new SqlCondition();
+
+    entryKeywords.forEach(function(entry) 
+    {
+        if (include)
+        {
+            typeCondition.orPrepare("SALESPROJECT_CLASSIFICATION.TYPE", entry[0], "# = ?");
+        }
+        else
+        {
+            typeCondition.andPrepare("SALESPROJECT_CLASSIFICATION.TYPE", entry[0], "# <> ?");
+        }
+    });
+    
+    resultingCondition.andSqlCondition(typeCondition, "1 = 0");
+    return resultingCondition;
+}
+----