fixed bug with replacing literal '?' with NULL

Author: chernser

jdbc-v2/src/main/java/com/clickhouse/jdbc/PreparedStatementImpl.java

@@ -314,6 +314,7 @@ public ResultSetMetaData getMetaData() throws SQLException {
             // before execution
             if (statementType == StatementType.SELECT) {
                 try {
+                    // Replace '?' with NULL to make SQL valid for DESCRIBE
                     String sql = JdbcUtils.replaceQuestionMarks(originalSql, JdbcUtils.NULL);
                     TableSchema tSchema = connection.getClient().getTableSchemaFromQuery(sql);
                     resultSetMetaData = new ResultSetMetaDataImpl(tSchema.getColumns(),

jdbc-v2/src/main/java/com/clickhouse/jdbc/internal/JdbcUtils.java

@@ -287,7 +287,7 @@ public static String escapeQuotes(String str) {
 
     public static final String NULL = "NULL";
 
-    private static final Pattern REPLACE_Q_MARK_PATTERN = Pattern.compile("(\"[^\"]*\"|`[^`]*`)|(\\?)");
+    private static final Pattern REPLACE_Q_MARK_PATTERN = Pattern.compile("(\"[^\"]*\"|`[^`]*`|'[^']*')|(\\?)");
 
     public static String replaceQuestionMarks(String sql, String replacement) {
         Matcher matcher = REPLACE_Q_MARK_PATTERN.matcher(sql);

jdbc-v2/src/test/java/com/clickhouse/jdbc/PreparedStatementTest.java

@@ -337,7 +337,6 @@ void testGetMetadata(String sql, int colCountBeforeExecution, Object[] values,
             Assert.assertEquals(metadataRs.getColumnCount(), colCountBeforeExecution);
 
             for (int i = 1; i <= metadataRs.getColumnCount(); i++) {
-                System.out.println("label=" + metadataRs.getColumnName(i) + " type=" + metadataRs.getColumnType(i));
                 assertEquals(metadataRs.getSchemaName(i), stmt.getConnection().getSchema());
             }
 
@@ -353,7 +352,6 @@ void testGetMetadata(String sql, int colCountBeforeExecution, Object[] values,
             assertNotNull(metadataRs);
             assertEquals(metadataRs.getColumnCount(), colCountAfterExecution);
             for (int i = 1; i <= metadataRs.getColumnCount(); i++) {
-                System.out.println("label=" + metadataRs.getColumnName(i) + " type=" + metadataRs.getColumnType(i));
                 assertEquals(metadataRs.getSchemaName(i), stmt.getConnection().getSchema());
             }
         }
@@ -503,7 +501,10 @@ void testMetabaseBug01() throws Exception {
     void testStatementSplit() throws Exception {
         try (Connection conn = getJdbcConnection()) {
             try (Statement stmt = conn.createStatement()) {
-                stmt.execute("CREATE TABLE `with_complex_id` (`v?``1` Int32, \"v?\"\"2\" Int32,`v?\\`3` Int32, \"v?\\\"4\" Int32) ENGINE Memory;");
+                stmt.execute("CREATE TABLE IF NOT EXISTS `with_complex_id` (`v?``1` Int32, " +
+                        "\"v?\"\"2\" Int32,`v?\\`3` Int32, \"v?\\\"4\" Int32) ENGINE MergeTree ORDER BY ();");
+                stmt.execute("CREATE TABLE IF NOT EXISTS `test_stmt_split2` (v1 Int32, v2 String) ENGINE MergeTree ORDER BY (); ");
+                stmt.execute("INSERT INTO `test_stmt_split2` VALUES (1, 'abc'), (2, '?'), (3, '?')");
             }
             String insertQuery = "-- line comment1 ?\n"
                     + "# line comment2 ?\n"
@@ -536,6 +537,20 @@ void testStatementSplit() throws Exception {
                     assertEquals(rs.getString(7), "test string3 ?\\");
                 }
             }
+
+            try (PreparedStatement stmt = conn.prepareStatement("SELECT v1 FROM `test_stmt_split2` WHERE v1 > ? AND v2 = '?'")) {
+                stmt.setInt(1, 2);
+                try (ResultSet rs = stmt.executeQuery()) {
+                    int count = 0;
+                    while (rs.next()) {
+                        count++;
+                        assertEquals(rs.getInt(1), 3);
+                    }
+
+                    Assert.assertEquals(count, 1);
+                }
+            }
+
         }
     }
 }

jdbc-v2/src/test/java/com/clickhouse/jdbc/internal/JdbcUtilsTest.java

@@ -1,5 +1,6 @@
 package com.clickhouse.jdbc.internal;
 
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 import java.util.List;
@@ -57,4 +58,20 @@ public void testEscapeQuotes() {
             assertEquals(JdbcUtils.escapeQuotes(inStr[i]), outStr[i]);
         }
     }
+
+    @Test(dataProvider = "testReplaceQuestionMark_dataProvider")
+    public void testReplaceQuestionMark(String sql, String result) {
+        assertEquals(JdbcUtils.replaceQuestionMarks(sql, "NULL"), result);
+    }
+
+    @DataProvider(name = "testReplaceQuestionMark_dataProvider")
+    public static Object[][] testReplaceQuestionMark_dataProvider() {
+        return new Object[][] {
+                {"", ""},
+                {"     ", "     "},
+                {"SELECT * FROM t WHERE a = '?'", "SELECT * FROM t WHERE a = '?'"},
+                {"SELECT `v2?` FROM t WHERE `v1?` = ?", "SELECT `v2?` FROM t WHERE `v1?` = NULL"},
+                {"INSERT INTO \"t2?\" VALUES (?, ?, 'some_?', ?)", "INSERT INTO \"t2?\" VALUES (NULL, NULL, 'some_?', NULL)"}
+        };
+    }
 }