SONAR-14335 Improve coverage

- drop unused class

server/sonar-db-migration/src/main/java/org/sonar/server/platform/db/migration/sql/DbPrimaryKeyConstraintFinder.java

 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.Locale;
-import java.util.Optional;
+import java.util.function.Supplier;
 import org.sonar.db.Database;
 import org.sonar.db.dialect.Dialect;
 import org.sonar.db.dialect.H2;
 
   public String findConstraintName(String tableName) throws SQLException {
     String constraintQuery = getDbVendorSpecificQuery(tableName);
-    return executeQuery(constraintQuery)
-      .orElseThrow(() -> constraintNotFoundException(tableName));
+    return executeQuery(constraintQuery, () -> constraintNotFoundException(tableName));
   }
 
   String getDbVendorSpecificQuery(String tableName) {
     return constraintQuery;
   }
 
-  private Optional<String> executeQuery(String query) throws SQLException {
+  private String executeQuery(String query, Supplier<? extends RuntimeException> exceptionSupplier) throws SQLException {
     try (Connection connection = db.getDataSource().getConnection();
       PreparedStatement pstmt = connection
         .prepareStatement(query);
       ResultSet rs = pstmt.executeQuery()) {
       if (rs.next()) {
-        return Optional.ofNullable(rs.getString(1));
+        return rs.getString(1);
       }
-      return Optional.empty();
+      throw exceptionSupplier.get();
     }
   }
 
 
   // FIXME:: this method should be moved somewhere else
   String getPostgresSqlSequence(String tableName, String columnName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-      PreparedStatement pstmt = connection.prepareStatement(format("SELECT pg_get_serial_sequence('%s', '%s')", tableName, columnName));
-      ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw new IllegalStateException(format("Cannot find sequence for table '%s' on column '%s'", tableName, columnName));
-    }
+    return executeQuery(format("SELECT pg_get_serial_sequence('%s', '%s')", tableName, columnName),
+      () -> new IllegalStateException(format("Cannot find sequence for table '%s' on column '%s'", tableName, columnName)));
   }
 
 }

server/sonar-db-migration/src/main/java/org/sonar/server/platform/db/migration/version/v84/util/SqlHelper.java

-/*
- * SonarQube
- * Copyright (C) 2009-2020 SonarSource SA
- * mailto:info AT sonarsource DOT com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 3 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- */
-package org.sonar.server.platform.db.migration.version.v84.util;
-
-import java.sql.Connection;
-import java.sql.PreparedStatement;
-import java.sql.ResultSet;
-import java.sql.SQLException;
-import java.util.Locale;
-import org.sonar.db.Database;
-
-import static java.lang.String.format;
-
-public class SqlHelper {
-
-  private final Database db;
-
-  public SqlHelper(Database db) {
-    this.db = db;
-  }
-
-  String getH2Constraint(String tableName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-      PreparedStatement pstmt = connection
-        .prepareStatement(format("SELECT constraint_name "
-          + "FROM information_schema.constraints "
-          + "WHERE table_name = '%s' and constraint_type = 'PRIMARY KEY'", tableName.toUpperCase(Locale.ENGLISH)));
-      ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw contraintNotFoundException(tableName);
-    }
-  }
-
-  String getPostgresSqlConstraint(String tableName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-      PreparedStatement pstmt = connection
-        .prepareStatement(format("SELECT conname " +
-          "FROM pg_constraint " +
-          "WHERE conrelid = " +
-          "    (SELECT oid " +
-          "    FROM pg_class " +
-          "    WHERE relname LIKE '%s')", tableName));
-      ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw contraintNotFoundException(tableName);
-    }
-  }
-
-  String getPostgresSqlSequence(String tableName, String columnName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-         PreparedStatement pstmt = connection
-           .prepareStatement(format("SELECT pg_get_serial_sequence('%s', '%s')", tableName, columnName));
-         ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw new IllegalStateException(format("Cannot find sequence for table '%s' on column '%s'", tableName, columnName));
-    }
-  }
-
-  String getOracleConstraint(String tableName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-      PreparedStatement pstmt = connection
-        .prepareStatement(format("SELECT constraint_name " +
-          "FROM user_constraints " +
-          "WHERE table_name = UPPER('%s') " +
-          "AND constraint_type='P'", tableName));
-      ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw contraintNotFoundException(tableName);
-    }
-  }
-
-  String getMssqlConstraint(String tableName) throws SQLException {
-    try (Connection connection = db.getDataSource().getConnection();
-      PreparedStatement pstmt = connection
-        .prepareStatement(format("SELECT name " +
-          "FROM sys.key_constraints " +
-          "WHERE type = 'PK' " +
-          "AND OBJECT_NAME(parent_object_id) = '%s'", tableName));
-      ResultSet rs = pstmt.executeQuery()) {
-      if (rs.next()) {
-        return rs.getString(1);
-      }
-      throw contraintNotFoundException(tableName);
-    }
-  }
-
-  private static IllegalStateException contraintNotFoundException(String tableName) {
-    return new IllegalStateException(format("Cannot find constraint for table '%s'", tableName));
-  }
-
-}

server/sonar-db-migration/src/test/java/org/sonar/server/platform/db/migration/sql/DbPrimaryKeyConstraintFinderTest.java

 import org.junit.Test;
 import org.sonar.db.CoreDbTester;
 import org.sonar.db.Database;
+import org.sonar.db.dialect.Dialect;
 import org.sonar.db.dialect.H2;
 import org.sonar.db.dialect.MsSql;
 import org.sonar.db.dialect.Oracle;
     assertThat(underTest.getDbVendorSpecificQuery("my_table"))
       .isEqualTo("SELECT constraint_name FROM information_schema.constraints WHERE table_name = 'MY_TABLE' and constraint_type = 'PRIMARY KEY'");
   }
+
+  @Test
+  public void getDbVendorSpecificQuery_unknown() {
+    Dialect mockDialect = mock(Dialect.class);
+    when(mockDialect.getId()).thenReturn("unknown");
+    when(dbMock.getDialect()).thenReturn(mockDialect);
+
+    assertThatThrownBy(() -> underTest.getDbVendorSpecificQuery("my_table"))
+      .isInstanceOf(IllegalStateException.class)
+      .hasMessage("Unsupported database 'unknown'");
+  }
 }