add teradata support

src/main/java/com/alibaba/druid/sql/dialect/teradata/ast/TeradataObject.java

@@ -0,0 +1,7 @@
+package com.alibaba.druid.sql.dialect.teradata.ast;
+
+import com.alibaba.druid.sql.ast.SQLObject;
+
+public interface TeradataObject extends SQLObject {
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/parser/TeradataExprParser.java

@@ -0,0 +1,24 @@
+package com.alibaba.druid.sql.dialect.teradata.parser;
+
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.SQLExprParser;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class TeradataExprParser extends SQLExprParser {
+
+    public final static String[] AGGREGATE_FUNCTIONS = { "AVG", "COUNT", "MAX", "MIN", "STDDEV", "SUM", "ROW_NUMBER" };
+
+    public TeradataExprParser(String sql){
+        this(new TeradataLexer(sql));
+        this.lexer.nextToken();
+        this.dbType = JdbcConstants.TERADATA;
+    }
+
+    public TeradataExprParser(Lexer lexer){
+        super(lexer);
+        this.aggregateFunctions = AGGREGATE_FUNCTIONS;
+        this.dbType = JdbcConstants.TERADATA;
+    }
+    
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/parser/TeradataLexer.java

@@ -0,0 +1,25 @@
+package com.alibaba.druid.sql.dialect.teradata.parser;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.alibaba.druid.sql.parser.Keywords;
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.Token;
+
+public class TeradataLexer extends Lexer {
+    public final static Keywords DEFAULT_PG_KEYWORDS;
+
+    static {
+        Map<String, Token> map = new HashMap<String, Token>();
+        map.putAll(Keywords.DEFAULT_KEYWORDS.getKeywords());
+        
+        DEFAULT_PG_KEYWORDS = new Keywords(map);
+    }
+    
+    public TeradataLexer(String input){
+        super(input);
+        super.keywods = DEFAULT_PG_KEYWORDS;
+    }
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/parser/TeradataStatementParser.java

@@ -0,0 +1,16 @@
+package com.alibaba.druid.sql.dialect.teradata.parser;
+
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+
+public class TeradataStatementParser extends SQLStatementParser {
+
+    public TeradataStatementParser(String sql){
+        super(new TeradataExprParser(sql));
+    }
+
+    public TeradataStatementParser(Lexer lexer){
+        super(new TeradataExprParser(lexer));
+    }
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/visitor/TeradataASTVisitor.java

@@ -0,0 +1,7 @@
+package com.alibaba.druid.sql.dialect.teradata.visitor;
+
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public interface TeradataASTVisitor extends SQLASTVisitor {
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/visitor/TeradataASTVisitorAdapter.java

@@ -0,0 +1,7 @@
+package com.alibaba.druid.sql.dialect.teradata.visitor;
+
+import com.alibaba.druid.sql.visitor.SQLASTVisitorAdapter;
+
+public class TeradataASTVisitorAdapter extends SQLASTVisitorAdapter implements TeradataASTVisitor {
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/visitor/TeradataOutputVisitor.java

@@ -0,0 +1,11 @@
+package com.alibaba.druid.sql.dialect.teradata.visitor;
+
+import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
+
+public class TeradataOutputVisitor extends SQLASTOutputVisitor implements TeradataASTVisitor {
+
+    public TeradataOutputVisitor(Appendable appender){
+        super(appender);
+    }
+
+}

src/main/java/com/alibaba/druid/sql/dialect/teradata/visitor/TeradataSchemaStatVisitor.java

@@ -0,0 +1,13 @@
+package com.alibaba.druid.sql.dialect.teradata.visitor;
+
+import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
+import com.alibaba.druid.util.JdbcUtils;
+
+public class TeradataSchemaStatVisitor extends SchemaStatVisitor implements TeradataASTVisitor {
+
+    @Override
+    public String getDbType() {
+        return JdbcUtils.POSTGRESQL;
+    }
+
+}