WIP on count impl; reworking comparisons

src/main/kotlin/query/Definition.kt

@@ -1,9 +1,6 @@
 package solutions.bitbadger.documents.query
 
-import solutions.bitbadger.documents.Configuration
-import solutions.bitbadger.documents.Dialect
-import solutions.bitbadger.documents.Field
-import solutions.bitbadger.documents.FieldFormat
+import solutions.bitbadger.documents.*
 
 /**
  * Functions to create queries to define tables and indexes
@@ -76,4 +73,20 @@ object Definition {
      */
     fun ensureKey(tableName: String, dialect: Dialect? = null) =
         ensureIndexOn(tableName, "key", listOf(Configuration.idField), dialect).replace("INDEX", "UNIQUE INDEX")
+
+    /**
+     * Create a document-wide index on a table (PostgreSQL only)
+     *
+     * @param tableName The name of the table on which the document index should be created
+     * @param indexType The type of index to be created
+     * @return The SQL statement to create an index on JSON documents in the specified table
+     * @throws DocumentException If the database mode is not PostgreSQL
+     */
+    fun ensureDocumentIndexOn(tableName: String, indexType: DocumentIndex): String {
+        if (Configuration.dialect("create document index query") != Dialect.POSTGRESQL) {
+            throw DocumentException("'Document indexes are only supported on PostgreSQL")
+        }
+        val (_, tbl) = splitSchemaAndTable(tableName)
+        return "CREATE INDEX IF NOT EXISTS idx_${tbl}_document ON $tableName USING GIN (data${indexType.sql})";
+    }
 }