supporting PG syntax 'ALTER COLUMN ... SET DATA TYPE ...'

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

@@ -787,6 +787,12 @@ protected SQLAlterTableAlterColumn parseAlterColumn() {
                     lexer.nextToken();
                     accept(Token.NULL);
                     alterColumn.setSetNotNull(true);
+                } else if (lexer.identifierEquals("DATA")) {
+                    // alter column ... set data type ...
+                    lexer.nextToken();
+                    accept(Token.TYPE);
+                    SQLDataType dataType = this.exprParser.parseDataType();
+                    alterColumn.setDataType(dataType);
                 } else {
                     accept(Token.DEFAULT);
                     SQLExpr defaultValue = this.exprParser.expr();

core/src/test/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSQLStatementParserTest.java

@@ -0,0 +1,108 @@
+package com.alibaba.druid.sql.dialect.postgresql.parser;
+
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableAlterColumn;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author gaattc
+ * @since 1.2.24
+ */
+public class PGSQLStatementParserTest {
+
+    /**
+     * ALTER COLUMN ... SET DATA TYPE ...
+     */
+    @Test
+    public void testAlterColumnSetDataType() {
+        String sql = "alter table if exists products alter column price set data type decimal(12,2)";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+
+        assertEquals(1, statementList.size());
+        SQLAlterTableStatement stmt = (SQLAlterTableStatement) statementList.get(0);
+        assertEquals(SQLAlterTableStatement.class, stmt.getClass());
+
+        assertEquals("products", stmt.getTableName());
+        assertTrue(stmt.isIfExists());
+
+        SQLAlterTableAlterColumn alterColumnItem = (SQLAlterTableAlterColumn) stmt.getItems().get(0);
+        assertNotNull(alterColumnItem);
+
+        assertEquals("price", alterColumnItem.getColumn().getName().getSimpleName());
+        assertNotNull(alterColumnItem.getDataType());
+        assertEquals("decimal", alterColumnItem.getDataType().getName().toLowerCase());
+        assertEquals(2, alterColumnItem.getDataType().getArguments().size());
+        assertEquals("12", alterColumnItem.getDataType().getArguments().get(0).toString());
+        assertEquals("2", alterColumnItem.getDataType().getArguments().get(1).toString());
+
+        String outputSql = stmt.toString();
+        assertEquals("ALTER TABLE IF EXISTS products\n\tALTER COLUMN price SET DATA TYPE decimal(12, 2)", outputSql);
+    }
+
+    /**
+     * ALTER COLUMN ... SET DEFAULT ...
+     */
+    @Test
+    public void testAlterColumnSetDefault() {
+        String sql = "ALTER TABLE products ALTER COLUMN price SET DEFAULT 7.77";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLAlterTableStatement stmt = (SQLAlterTableStatement) statementList.get(0);
+
+        SQLAlterTableAlterColumn alterColumnItem = (SQLAlterTableAlterColumn) stmt.getItems().get(0);
+
+        assertEquals("price", alterColumnItem.getColumn().getName().getSimpleName());
+        assertNotNull(alterColumnItem.getSetDefault());
+        assertEquals("7.77", alterColumnItem.getSetDefault().toString());
+        assertNull(alterColumnItem.getDataType());
+    }
+
+    /**
+     * ALTER COLUMN ... SET NOT NULL
+     */
+    @Test
+    public void testAlterColumnSetNotNull() {
+        String sql = "ALTER TABLE products ALTER COLUMN price SET NOT NULL";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLAlterTableStatement stmt = (SQLAlterTableStatement) statementList.get(0);
+
+        SQLAlterTableAlterColumn alterColumnItem = (SQLAlterTableAlterColumn) stmt.getItems().get(0);
+
+        assertEquals("price", alterColumnItem.getColumn().getName().getSimpleName());
+        assertTrue(alterColumnItem.isSetNotNull());
+        assertNull(alterColumnItem.getDataType());
+    }
+
+    /**
+     * DROP
+     */
+    @Test
+    public void testAlterColumnDropDefault() {
+        String sql = "ALTER TABLE products ALTER COLUMN price DROP DEFAULT";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLAlterTableStatement stmt = (SQLAlterTableStatement) statementList.get(0);
+
+        SQLAlterTableAlterColumn alterColumnItem = (SQLAlterTableAlterColumn) stmt.getItems().get(0);
+
+        assertEquals("price", alterColumnItem.getColumn().getName().getSimpleName());
+        assertTrue(alterColumnItem.isDropDefault());
+        assertNull(alterColumnItem.getDataType());
+    }
+
+
+}