fixes #34

Author: wumpz

README.md

@@ -26,6 +26,20 @@ configuration details below.
 JSqlParser parses an SQL statement and translate it into a hierarchy of Java classes. 
 The generated hierarchy can be navigated using the Visitor Pattern.
 
+## Extensions Version 0.8.9
+
+* Added **CCJSqlParserUtil.parseExpression** to parse a simple expression. Now you can build expressions from a String like "a+b".
+
+```java
+Expression expr = CCJSqlParserUtil.parseExpression("a*(5+mycolumn)");
+```
+
+* Improved **SelectUtils** to build simple select statements.
+
+```java
+Select select = SelectUtils.buildSelectFromTable(new Table("mytable"));
+```
+
 ## Extensions Version 0.8.8
 
 * Startet a simple utility class **SelectUtils** to collect basic **select** modification tools.

src/main/java/net/sf/jsqlparser/parser/CCJSqlParserUtil.java

@@ -25,6 +25,7 @@
 import java.io.Reader;
 import java.io.StringReader;
 import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.statement.Statement;
 
 /**
@@ -67,6 +68,21 @@ public static Statement parse(InputStream is, String encoding) throws JSQLParser
 			throw new JSQLParserException(ex);
 		} 
 	}
+	
+	/**
+	 * Parse an expression.
+	 * @param expression
+	 * @return
+	 * @throws JSQLParserException 
+	 */
+	public static Expression parseExpression(String expression) throws JSQLParserException {
+		CCJSqlParser parser = new CCJSqlParser(new StringReader(expression));
+		try {
+			return parser.SimpleExpression();
+		} catch (Exception ex) {
+			throw new JSQLParserException(ex);
+		} 
+	}
 
 	private CCJSqlParserUtil() {
 	}

src/main/java/net/sf/jsqlparser/statement/select/PlainSelect.java

@@ -21,6 +21,8 @@
  */
 package net.sf.jsqlparser.statement.select;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.schema.Table;
 
@@ -85,6 +87,13 @@ public void setInto(Table table) {
 	public void setSelectItems(List<SelectItem> list) {
 		selectItems = list;
 	}
+	
+	public void addSelectItems(SelectItem ... items) {
+		if (selectItems == null) {
+			selectItems = new ArrayList<SelectItem>();
+		}
+		Collections.addAll(selectItems, items);
+	}
 
 	public void setWhere(Expression where) {
 		this.where = where;

src/main/java/net/sf/jsqlparser/util/SelectUtils.java

@@ -22,13 +22,19 @@
 package net.sf.jsqlparser.util;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.parser.CCJSqlParserUtil;
+import net.sf.jsqlparser.schema.Column;
 import net.sf.jsqlparser.schema.Table;
+import net.sf.jsqlparser.statement.select.AllColumns;
 import net.sf.jsqlparser.statement.select.Join;
 import net.sf.jsqlparser.statement.select.PlainSelect;
 import net.sf.jsqlparser.statement.select.Select;
 import net.sf.jsqlparser.statement.select.SelectExpressionItem;
+import net.sf.jsqlparser.statement.select.SelectItem;
 import net.sf.jsqlparser.statement.select.SelectVisitor;
 import net.sf.jsqlparser.statement.select.SetOperationList;
 import net.sf.jsqlparser.statement.select.WithItem;
@@ -42,6 +48,53 @@ public final class SelectUtils {
 
 	private SelectUtils() {
 	}
+	
+	/**
+	 * Builds select expr1, expr2 from table.
+	 * @param table
+	 * @param expr
+	 * @return 
+	 */
+	public static Select buildSelectFromTableAndExpressions(Table table, Expression ... expr) {
+		SelectItem[] list = new SelectItem[expr.length];
+		for (int i=0;i<expr.length;i++) {
+			list[i]=new SelectExpressionItem(expr[i]);
+		}
+		return buildSelectFromTableAndSelectItems(table, list);
+	}
+	
+	/**
+	 * Builds select expr1, expr2 from table.
+	 * @param table
+	 * @param expr
+	 * @return 
+	 * @throws net.sf.jsqlparser.JSQLParserException 
+	 */
+	public static Select buildSelectFromTableAndExpressions(Table table, String ... expr) throws JSQLParserException {
+		SelectItem[] list = new SelectItem[expr.length];
+		for (int i=0;i<expr.length;i++) {
+			list[i]=new SelectExpressionItem(CCJSqlParserUtil.parseExpression(expr[i]));
+		}
+		return buildSelectFromTableAndSelectItems(table, list);
+	}
+	
+	public static Select buildSelectFromTableAndSelectItems(Table table, SelectItem ... selectItems) {
+		Select select = new Select();
+		PlainSelect body = new PlainSelect();
+		body.addSelectItems(selectItems);
+		body.setFromItem(table);
+		select.setSelectBody(body);
+		return select;
+	}
+	
+	/**
+	 * Builds select * from table.
+	 * @param table
+	 * @return 
+	 */
+	public static Select buildSelectFromTable(Table table) {
+		return buildSelectFromTableAndSelectItems(table, new AllColumns());
+	}
 
 	/**
 	 * Adds an expression to select statements. E.g. a simple column is an

src/test/java/net/sf/jsqlparser/parser/CCJSqlParserUtilTest.java

@@ -0,0 +1,63 @@
+package net.sf.jsqlparser.parser;
+
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.expression.LongValue;
+import net.sf.jsqlparser.expression.Parenthesis;
+import net.sf.jsqlparser.expression.operators.arithmetic.Addition;
+import net.sf.jsqlparser.expression.operators.arithmetic.Multiplication;
+import net.sf.jsqlparser.schema.Column;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ *
+ * @author toben
+ */
+public class CCJSqlParserUtilTest {
+	
+	public CCJSqlParserUtilTest() {
+	}
+	
+	@BeforeClass
+	public static void setUpClass() {
+	}
+	
+	@AfterClass
+	public static void tearDownClass() {
+	}
+	
+	@Before
+	public void setUp() {
+	}
+	
+	@After
+	public void tearDown() {
+	}
+
+	/**
+	 * Test of parseExpression method, of class CCJSqlParserUtil.
+	 */
+	@Test
+	public void testParseExpression() throws Exception {
+		Expression result = CCJSqlParserUtil.parseExpression("a+b");
+		assertEquals("a + b", result.toString());
+		assertTrue(result instanceof Addition);
+		Addition add = (Addition)result;
+		assertTrue(add.getLeftExpression() instanceof Column);
+		assertTrue(add.getRightExpression() instanceof Column);
+	}
+	
+	@Test
+	public void testParseExpression2() throws Exception {
+		Expression result = CCJSqlParserUtil.parseExpression("2*(a+6.0)");
+		assertEquals("2 * (a + 6.0)", result.toString());
+		assertTrue(result instanceof Multiplication);
+		Multiplication mult = (Multiplication)result;
+		assertTrue(mult.getLeftExpression() instanceof LongValue);
+		assertTrue(mult.getRightExpression() instanceof Parenthesis);
+	}
+}

src/test/java/net/sf/jsqlparser/util/SelectUtilsTest.java

@@ -1,14 +1,17 @@
 package net.sf.jsqlparser.util;
 
 import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.LongValue;
 import net.sf.jsqlparser.expression.operators.arithmetic.Addition;
 import net.sf.jsqlparser.expression.operators.relational.EqualsTo;
 import net.sf.jsqlparser.parser.CCJSqlParserUtil;
 import net.sf.jsqlparser.schema.Column;
 import net.sf.jsqlparser.schema.Table;
 import net.sf.jsqlparser.statement.select.Join;
+import net.sf.jsqlparser.statement.select.PlainSelect;
 import net.sf.jsqlparser.statement.select.Select;
+import net.sf.jsqlparser.statement.select.SelectExpressionItem;
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -68,4 +71,25 @@ public void testAddJoin() throws JSQLParserException {
 		addJoin.setLeft(true);
 		assertEquals("SELECT a FROM mytable LEFT JOIN mytable2 ON a = b", select.toString());
 	}
+	
+	@Test
+	public void testBuildSelectFromTableAndExpressions() {
+		Select select = SelectUtils.buildSelectFromTableAndExpressions(new Table("mytable"), new Column("a"), new Column("b"));
+		assertEquals("SELECT a, b FROM mytable", select.toString());
+	}
+	
+	@Test
+	public void testBuildSelectFromTable() {
+		Select select = SelectUtils.buildSelectFromTable(new Table("mytable"));
+		assertEquals("SELECT * FROM mytable", select.toString());
+	}
+	
+	@Test
+	public void testBuildSelectFromTableAndParsedExpression() throws JSQLParserException {
+		Select select = SelectUtils.buildSelectFromTableAndExpressions(new Table("mytable"), "a+b", "test");
+		assertEquals("SELECT a + b, test FROM mytable", select.toString());
+		
+		assertTrue(((SelectExpressionItem)((PlainSelect)select.getSelectBody()).getSelectItems().get(0)).getExpression() instanceof Addition);
+	}
+	
 }