doc: explain the TablesNamesFinder, fix the example

Signed-off-by: Andreas Reichel <andreas@manticore-projects.com>

Author: manticore-projects

src/site/sphinx/usage.rst

@@ -200,7 +200,7 @@ The class ``net.sf.jsqlparser.util.TablesNamesFinder`` can be used to return all
 
      // find in Expressions
      String exprStr = "A.id=B.id and A.age = (select age from C)";
-     tableNames = TablesNamesFinder.findTables(sqlStr);
+     tableNames = TablesNamesFinder.findTablesInExpression(exprStr);
      assertThat( tableNames ).containsExactlyInAnyOrder("A", "B", "C");
 
 

src/test/java/net/sf/jsqlparser/util/TablesNamesFinderTest.java

@@ -493,7 +493,7 @@ void testJoinSubSelect() throws JSQLParserException {
         assertThat( tableNames ).containsExactlyInAnyOrder("A", "B", "C");
 
         String exprStr = "A.id=B.id and A.age = (select age from C)";
-        tableNames = TablesNamesFinder.findTables(sqlStr);
+        tableNames = TablesNamesFinder.findTablesInExpression(exprStr);
         assertThat( tableNames ).containsExactlyInAnyOrder("A", "B", "C");
     }
 }