bug fixed for sql parser for postgresql, for issue 1204, https://github.com/alibaba/druid/issues/1204

src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGExprParser.java

@@ -65,6 +65,10 @@ public class PGExprParser extends SQLExprParser {
         }
         return super.parseDataType();
     }
+    
+    public PGSelectParser createSelectParser() {
+        return new PGSelectParser(this);
+    }
 
     public SQLExpr primary() {
         if (lexer.token() == Token.ARRAY) {

src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGResourceTest.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 1999-2101 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.postgresql;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.List;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.OracleTest;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlParameterizedOutputVisitor;
+import com.alibaba.druid.sql.dialect.oracle.parser.OracleStatementParser;
+import com.alibaba.druid.sql.dialect.oracle.visitor.OracleSchemaStatVisitor;
+import com.alibaba.druid.util.Utils;
+import com.alibaba.druid.util.JdbcUtils;
+
+public class PGResourceTest extends OracleTest {
+
+    public void test_0() throws Exception {
+        // 13
+//        exec_test("bvt/parser/oracle-56.txt");
+        for (int i = 0; i < 1; ++i) {
+             exec_test("bvt/parser/pg-" + i + ".txt");
+        }
+    }
+
+    public void exec_test(String resource) throws Exception {
+        System.out.println(resource);
+        InputStream is = null;
+
+        is = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
+        Reader reader = new InputStreamReader(is, "UTF-8");
+        String input = Utils.read(reader);
+        JdbcUtils.close(reader);
+        String[] items = input.split("---------------------------");
+        String sql = items[0].trim();
+        String expect = items[1].trim();
+
+        OracleStatementParser parser = new OracleStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+
+        // Assert.assertEquals(1, statementList.size());
+
+        System.out.println(sql);
+
+        print(statementList);
+
+        OracleSchemaStatVisitor visitor = new OracleSchemaStatVisitor();
+
+        for (int i = 0, size = statementList.size(); i < size; ++i) {
+            SQLStatement statement = statementList.get(i);
+            statement.accept(visitor);
+        }
+
+        System.out.println("Tables : " + visitor.getTables());
+        System.out.println("fields : " + visitor.getColumns());
+
+        System.out.println();
+        System.out.println();
+    }
+
+    void mergValidate(String sql, String expect) {
+
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLStatement statemen = statementList.get(0);
+
+        Assert.assertEquals(1, statementList.size());
+
+        StringBuilder out = new StringBuilder();
+        MySqlParameterizedOutputVisitor visitor = new MySqlParameterizedOutputVisitor(out);
+        statemen.accept(visitor);
+
+        System.out.println(out.toString());
+
+        Assert.assertEquals(expect, out.toString());
+    }
+
+}

src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGSelectTest25.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 1999-2101 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.postgresql;
+
+import java.util.List;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.PGTest;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.postgresql.parser.PGSQLStatementParser;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGSchemaStatVisitor;
+
+public class PGSelectTest25 extends PGTest {
+
+    public void test_0() throws Exception {
+        String sql = "select COALESCE((SELECT project_deduct_mandays from mytable_01 limit 1)) from t";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLStatement stmt = statementList.get(0);
+
+        Assert.assertEquals("SELECT COALESCE(("
+                + "\n\t\tSELECT project_deduct_mandays"
+                + "\n\t\tFROM mytable_01"
+                + "\n\t\tLIMIT 1"
+                + "\n\t\t))"
+                + "\nFROM t", SQLUtils.toPGString(stmt));
+        
+        Assert.assertEquals("select COALESCE(("
+                + "\n\t\tselect project_deduct_mandays"
+                + "\n\t\tfrom mytable_01"
+                + "\n\t\tlimit 1"
+                + "\n\t\t))"
+                + "\nfrom t", SQLUtils.toPGString(stmt, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION));
+
+        Assert.assertEquals(1, statementList.size());
+
+        PGSchemaStatVisitor visitor = new PGSchemaStatVisitor();
+        stmt.accept(visitor);
+
+//        System.out.println("Tables : " + visitor.getTables());
+//        System.out.println("fields : " + visitor.getColumns());
+//        System.out.println("coditions : " + visitor.getConditions());
+
+        Assert.assertEquals(1, visitor.getColumns().size());
+        Assert.assertEquals(2, visitor.getTables().size());
+    }
+}