Made pronunciation::rhymes join dynamic

This involved adding a new type of filter; one that compares (currently
only equality and inequality) a field with another field located in an
enclosing join context.

In the process, it was discovered that simplifying the lemma::forms join
field earlier actually made some queries return inaccurate results
because the inflection of the form was being ignored and anything in the
lemma would be used because of the inner join. Because the existing
condition join did not allow for the condition field to be on the from
side of the join, two things were done: a condition version of
joinThrough was made, and lemma was finally eliminated as a top-level
object, replaced instead with a condition join between word and form
through lemmas_forms.

Queries are also now grouped by the first select field (assumed to be
the primary ID) of the top table, in order to eliminate duplicates
created by inner joins, so that there is a uniform distribution between
results for random queries.

Created a database index on pronunciations(rhyme) which decreases query
time for rhyming filters. The new database version is
backwards-compatible because no data or structure changed.

1 files changed, 33 insertions, 28 deletions

@@ -19,6 +19,7 @@ namespace verbly {
       join,
       join_where,
       join_through,
+      join_through_where,
       hierarchal_join
     };
 
@@ -100,11 +101,11 @@ namespace verbly {
       object obj,
       const char* name,
       object joinWith,
-      const field& conditionField,
+      const char* conditionColumn,
       int conditionValue,
       bool nullable = false)
     {
-      return field(obj, type::join_where, name, nullable, 0, joinWith, 0, 0, 0, &conditionField, conditionValue);
+      return field(obj, type::join_where, name, nullable, 0, joinWith, 0, 0, 0, conditionColumn, conditionValue);
     }
 
     static field joinThrough(
@@ -129,6 +130,19 @@ namespace verbly {
       return field(obj, type::join_through, name, true, joinTable, joinWith, foreignColumn, joinColumn, foreignJoinColumn);
     }
 
+    static field joinThroughWhere(
+      object obj,
+      const char* name,
+      object joinWith,
+      const char* joinTable,
+      const char* foreignColumn,
+      const char* conditionColumn,
+      int conditionValue,
+      bool nullable = false)
+    {
+      return field(obj, type::join_through_where, name, nullable, joinTable, joinWith, foreignColumn, name, foreignColumn, conditionColumn, conditionValue);
+    }
+
     static field selfJoin(
       object obj,
       const char* name,
@@ -166,6 +180,7 @@ namespace verbly {
       return ((type_ == type::join)
         || (type_ == type::join_where)
         || (type_ == type::join_through)
+        || (type_ == type::join_through_where)
         || (type_ == type::hierarchal_join));
     }
 
@@ -195,7 +210,7 @@ namespace verbly {
     {
       return (type_ == type::hierarchal_join)
         ? object_
-        : ((type_ == type::join) || (type_ == type::join_where) || (type_ == type::join_through))
+        : ((type_ == type::join) || (type_ == type::join_where) || (type_ == type::join_through) || (type_ == type::join_through_where))
         ? joinObject_
         : throw std::domain_error("Non-join fields don't have join objects");
     }
@@ -205,40 +220,40 @@ namespace verbly {
     const char* getForeignColumn() const
     {
       // We ignore hierarchal joins because they are always self joins.
-      return (type_ == type::join_through)
+      return ((type_ == type::join_through) || (type_ == type::join_through_where))
         ? foreignColumn_
         : throw std::domain_error("Only many-to-many join fields have a foreign column");
     }
 
     const char* getJoinColumn() const
     {
-      return ((type_ == type::join_through) || (type_ == type::hierarchal_join))
+      return ((type_ == type::join_through) || (type_ == type::join_through_where) || (type_ == type::hierarchal_join))
         ? joinColumn_
         : throw std::domain_error("Only many-to-many join fields have a join column");
     }
 
     const char* getForeignJoinColumn() const
     {
-      return ((type_ == type::join_through) || (type_ == type::hierarchal_join))
+      return ((type_ == type::join_through) || (type_ == type::join_through_where) || (type_ == type::hierarchal_join))
         ? foreignJoinColumn_
         : throw std::domain_error("Only many-to-many join fields have a foreign join column");
     }
 
     // Condition joins
 
-    const field& getConditionField() const
+    const char* getConditionColumn() const
     {
-      if (type_ == type::join_where)
+      if ((type_ == type::join_where) || (type_ == type::join_through_where))
       {
-        return *conditionField_;
+        return conditionColumn_;
       } else {
-        throw std::domain_error("Only condition join fields have a condition field");
+        throw std::domain_error("Only condition join fields have a condition column");
       }
     }
 
     int getConditionValue() const
     {
-      return (type_ == type::join_where)
+      return ((type_ == type::join_where) || (type_ == type::join_through_where))
         ? conditionValue_
         : throw std::domain_error("Only condition join fields have a condition value");
     }
@@ -254,13 +269,8 @@ namespace verbly {
       // table (hypernymy); however, they have different join columns. For
       // condition joins, the condition field and condition value are also
       // significant.
-      if (conditionField_)
-      {
-        return std::tie(object_, column_, table_, joinColumn_, *conditionField_, conditionValue_)
-          < std::tie(other.object_, other.column_, other.table_, other.joinColumn_, *other.conditionField_, other.conditionValue_);
-      } else {
-        return std::tie(object_, column_, table_, joinColumn_) < std::tie(other.object_, other.column_, other.table_, other.joinColumn_);
-      }
+      return std::tie(object_, column_, table_, joinColumn_, conditionColumn_, conditionValue_)
+        < std::tie(other.object_, other.column_, other.table_, other.joinColumn_, other.conditionColumn_, other.conditionValue_);
     }
 
     // Equality
@@ -268,13 +278,8 @@ namespace verbly {
     bool operator==(const field& other) const
     {
       // See operator<() for documentation.
-      if (conditionField_)
-      {
-        return std::tie(object_, column_, table_, joinColumn_, *conditionField_, conditionValue_)
-          == std::tie(other.object_, other.column_, other.table_, other.joinColumn_, *other.conditionField_, other.conditionValue_);
-      } else {
-        return std::tie(object_, column_, table_, joinColumn_) == std::tie(other.object_, other.column_, other.table_, other.joinColumn_);
-      }
+      return std::tie(object_, column_, table_, joinColumn_, conditionColumn_, conditionValue_)
+        == std::tie(other.object_, other.column_, other.table_, other.joinColumn_, other.conditionColumn_, other.conditionValue_);
     }
 
     // Filter construction
@@ -325,7 +330,7 @@ namespace verbly {
       const char* foreignColumn = 0,
       const char* joinColumn = 0,
       const char* foreignJoinColumn = 0,
-      const field* conditionField = 0,
+      const char* conditionColumn = 0,
       int conditionValue = 0) :
         object_(obj),
         type_(datatype),
@@ -336,7 +341,7 @@ namespace verbly {
         foreignColumn_(foreignColumn),
         joinColumn_(joinColumn),
         foreignJoinColumn_(foreignJoinColumn),
-        conditionField_(conditionField),
+        conditionColumn_(conditionColumn),
         conditionValue_(conditionValue)
     {
     }
@@ -359,7 +364,7 @@ namespace verbly {
     const char* foreignJoinColumn_ = 0;
 
     // Condition joins
-    const field* conditionField_ = 0;
+    const char* conditionColumn_ = 0;
     int conditionValue_ = 0;
 
   };