feat: add support for optional WHERE keyword in query syntax

querity-parser/src/main/antlr4/io/github/queritylib/querity/parser/QueryLexer.g4

@@ -22,6 +22,7 @@ PAGINATION  : P A G E;
 AS          : A S;
 GROUP_BY    : G R O U P ' ' B Y;
 HAVING      : H A V I N G;
+WHERE       : W H E R E;
 
 // Comparison operators
 NEQ         : '!=';

querity-parser/src/main/antlr4/io/github/queritylib/querity/parser/QueryParser.g4

@@ -3,7 +3,9 @@ parser grammar QueryParser;
 options { tokenVocab=QueryLexer; }
 
 // Main query structure
-query            : DISTINCT? (selectClause)? (condition)? (groupByClause)? (havingClause)? (SORT sortFields)? (PAGINATION paginationParams)? ;
+query            : DISTINCT? (selectClause)? (whereCondition)? (groupByClause)? (havingClause)? (SORT sortFields)? (PAGINATION paginationParams)? ;
+
+whereCondition   : WHERE? condition ;
 
 // Select clause with support for expressions and optional aliases
 selectClause     : SELECT selectFields ;

querity-parser/src/main/java/io/github/queritylib/querity/parser/QueryVisitor.java

@@ -13,7 +13,7 @@ class QueryVisitor extends QueryParserBaseVisitor<Object> {
   public QueryDefinition visitQuery(QueryParser.QueryContext ctx) {
     boolean distinct = ctx.DISTINCT() != null;
     Select select = ctx.selectClause() != null ? (Select) visit(ctx.selectClause()) : null;
-    Condition filter = ctx.condition() != null ? (Condition) visit(ctx.condition()) : null;
+    Condition filter = ctx.whereCondition() != null ? (Condition) visit(ctx.whereCondition()) : null;
     GroupBy groupBy = ctx.groupByClause() != null ? (GroupBy) visit(ctx.groupByClause()) : null;
     Condition having = ctx.havingClause() != null ? (Condition) visit(ctx.havingClause()) : null;
     Sort[] sorts = ctx.SORT() != null ? (Sort[]) visit(ctx.sortFields()) : new Sort[0];
@@ -41,6 +41,11 @@ public QueryDefinition visitQuery(QueryParser.QueryContext ctx) {
         .build();
   }
 
+  @Override
+  public Object visitWhereCondition(QueryParser.WhereConditionContext ctx) {
+    return visit(ctx.condition());
+  }
+
   @Override
   public Object visitSelectClause(QueryParser.SelectClauseContext ctx) {
     return visit(ctx.selectFields());

querity-parser/src/test/java/io/github/queritylib/querity/parser/QuerityParserTests.java

@@ -30,6 +30,8 @@ public static Stream<Arguments> provideSimpleQueryArguments() {
         Arguments.of("", Querity.query().build()),
         Arguments.of("lastName=\"Skywalker\"",
             Querity.query().filter(filterBy("lastName", "Skywalker")).build()),
+        Arguments.of("where lastName=\"Skywalker\"",
+            Querity.query().filter(filterBy("lastName", "Skywalker")).build()),
         Arguments.of("lastName!=\"Skywalker\"",
             Querity.query().filter(filterBy("lastName", NOT_EQUALS, "Skywalker")).build()),
         Arguments.of("lastName starts with \"Sky\"",
@@ -142,6 +144,8 @@ public static Stream<Arguments> provideAdvancedQueryArguments() {
             Querity.advancedQuery().selectBy("id").build()),
         Arguments.of("select id, name lastName=\"Skywalker\"",
             Querity.advancedQuery().selectBy("id", "name").filter(filterBy("lastName", "Skywalker")).build()),
+        Arguments.of("select id, name where lastName=\"Skywalker\"",
+            Querity.advancedQuery().selectBy("id", "name").filter(filterBy("lastName", "Skywalker")).build()),
         Arguments.of("select id, name lastName=\"Skywalker\" sort by name asc",
             Querity.advancedQuery().selectBy("id", "name").filter(filterBy("lastName", "Skywalker")).sort(sortBy("name", ASC)).build()),
         Arguments.of("select id, name lastName=\"Skywalker\" sort by name asc page 1,10",