improved sql parser. for issue #1979

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/ast/stmt/SQLServerSetStatement.java

@@ -23,8 +23,8 @@ import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerStatementImpl;
 import com.alibaba.druid.sql.dialect.sqlserver.visitor.SQLServerASTVisitor;
 
 public class SQLServerSetStatement extends SQLServerStatementImpl implements SQLServerStatement {
-
-    private SQLAssignItem item = new SQLAssignItem();
+    private Option        option;
+    private SQLAssignItem item    = new SQLAssignItem();
 
     public SQLServerSetStatement(){
     }
@@ -38,6 +38,9 @@ public class SQLServerSetStatement extends SQLServerStatementImpl implements SQL
     }
 
     public void setItem(SQLAssignItem item) {
+        if (item != null) {
+            item.setParent(this);
+        }
         this.item = item;
     }
 
@@ -46,6 +49,14 @@ public class SQLServerSetStatement extends SQLServerStatementImpl implements SQL
         item.output(buf);
     }
 
+    public Option getOption() {
+        return option;
+    }
+
+    public void setOption(Option option) {
+        this.option = option;
+    }
+
     @Override
     public void accept0(SQLServerASTVisitor visitor) {
         if (visitor.visit(this)) {
@@ -53,4 +64,13 @@ public class SQLServerSetStatement extends SQLServerStatementImpl implements SQL
         }
         visitor.endVisit(this);
     }
+
+    public void set(SQLExpr target, SQLExpr value) {
+        SQLAssignItem assignItem = new SQLAssignItem(target, value);
+        setItem(assignItem);
+    }
+
+    public static enum Option {
+        IDENTITY_INSERT
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerStatementParser.java

@@ -362,7 +362,7 @@ public class SQLServerStatementParser extends SQLStatementParser {
     public SQLStatement parseSet() {
         accept(Token.SET);
 
-        if (lexer.identifierEquals("TRANSACTION")) {
+        if (lexer.identifierEquals(FnvHash.Constants.TRANSACTION)) {
             lexer.nextToken();
             acceptIdentifier("ISOLATION");
             acceptIdentifier("LEVEL");
@@ -402,7 +402,7 @@ public class SQLServerStatementParser extends SQLStatementParser {
             return stmt;
         }
 
-        if (lexer.identifierEquals("STATISTICS")) {
+        if (lexer.identifierEquals(FnvHash.Constants.STATISTICS)) {
             lexer.nextToken();
 
             SQLServerSetStatement stmt = new SQLServerSetStatement();
@@ -415,7 +415,7 @@ public class SQLServerStatementParser extends SQLStatementParser {
                 if (lexer.token() == Token.ON) {
                     stmt.getItem().setValue(new SQLIdentifierExpr("ON"));
                     lexer.nextToken();
-                } else if (lexer.identifierEquals("OFF")) {
+                } else if (lexer.identifierEquals(FnvHash.Constants.OFF)) {
                     stmt.getItem().setValue(new SQLIdentifierExpr("OFF"));
                     lexer.nextToken();
                 }
@@ -423,6 +423,25 @@ public class SQLServerStatementParser extends SQLStatementParser {
             return stmt;
         }
 
+        if (lexer.identifierEquals(FnvHash.Constants.IDENTITY_INSERT)) {
+            SQLServerSetStatement stmt = new SQLServerSetStatement();
+            stmt.setOption(SQLServerSetStatement.Option.IDENTITY_INSERT);
+
+            lexer.nextToken();
+            SQLName table = this.exprParser.name();
+
+            if (lexer.token() == Token.ON) {
+                SQLExpr value = new SQLIdentifierExpr("ON");
+                stmt.set(table, value);
+                lexer.nextToken();
+            } else if (lexer.identifierEquals(FnvHash.Constants.OFF)) {
+                SQLExpr value = new SQLIdentifierExpr("OFF");
+                stmt.set(table, value);
+                lexer.nextToken();
+            }
+            return stmt;
+        }
+
         if (lexer.token() == Token.VARIANT) {
             SQLSetStatement stmt = new SQLSetStatement(getDbType());
             parseAssignItems(stmt.getItems(), stmt);

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerOutputVisitor.java

@@ -350,6 +350,13 @@ public class SQLServerOutputVisitor extends SQLASTOutputVisitor implements SQLSe
     @Override
     public boolean visit(SQLServerSetStatement x) {
         print0(ucase ? "SET " : "set ");
+
+        SQLServerSetStatement.Option option = x.getOption();
+        if (option != null) {
+            print(option.name());
+            print(' ');
+        }
+
         SQLAssignItem item = x.getItem();
         item.getTarget().accept(this);
         print(' ');

src/main/java/com/alibaba/druid/util/FnvHash.java

@@ -36,6 +36,25 @@ public final class FnvHash {
         return hash;
     }
 
+    public static long fnv1a_64(String input, int offset, int end) {
+        if (input == null) {
+            return 0;
+        }
+
+        if (input.length() < end) {
+            end = input.length();
+        }
+
+        long hash = BASIC;
+        for (int i = offset; i < end; ++i) {
+            char c = input.charAt(i);
+            hash ^= c;
+            hash *= PRIME;
+        }
+
+        return hash;
+    }
+
     public static long fnv1a_64(char[] chars) {
         if (chars == null) {
             return 0;