极方便的动态 SQL 生成工具代码,Java代码库,德仔网

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【Java】极方便的动态 SQL 生成工具
作者:mickelfeng / 发布于2014/6/9/ 954
超级好用的动态SQL生成工具： SQL.Select("*").From("user").Where("create_time>?", startTime).And("role in ?", roleList); 主要特点： 1、动态查询条件生成 2、自动生成 in 条件更多例子参见 SQLTest.java

	import org.junit.Test;

	import java.util.Arrays;
	import java.util.List;

	/**
	* todo: description
	*
	* @author yiding.he
	*/
	public class SQLTest {

	 private static void print(SQL.Generatable generatable) {
	 Command command = generatable.toCommand();
	 System.out.println(command.getStatement());
	 System.out.println(command.getParams());
	 System.out.println();
	 }

	 @Test
	 public void testSelect() throws Exception {
	 String usernamePrefix = "JOHN%";
	 String role = "admin";
	 String username = "admin";

	 print(
	 SQL.Select("*").From("USERS")
	 .Where("USERNAME like ?", usernamePrefix)
	 .And("(ROLE=?", role).Or("USERNAME=?)", username)
	 );

	 print(
	 SQL.Select("*").From("USERS")
	 .Where("USERNAME like ?", usernamePrefix)
	 .Append("and (")
	 .Append(role != null, "ROLE=?", role)
	 .Or("USERNAME=?", username)
	 .Append(")")
	 );

	 role = null;
	 print(
	 SQL.Select("count(1), ROLE")
	 .From("USERS")
	 .Where(false, "REGISTER_TIME>sysdate-1") // dismissed
	 .AndIfNotEmpty("ROLE=?", role) // dismissed
	 .And("1=1")
	 .GroupBy("ROLE")
	 );

	 List<Integer> levels = Arrays.asList(1, 2, 3);
	 print(
	 SQL.Select("*")
	 .From("USERS")
	 .Where("USER_LEVEL in ?", levels)
	 );

	 }

	 @Test
	 public void testUpdate() throws Exception {

	 print(
	 SQL.Update("USER")
	 .Set("AGE", 3)
	 .Set(false, "NAME", "admin").Where("ID=?", 1)
	 );
	 }

	 @Test
	 public void testInsert() throws Exception {
	 print(
	 SQL.Insert("USER")
	 .Values("ID", 1)
	 .Values("USERNAME", "admin")
	 .Values("PASSWORD", "admin")
	 .Values("AGE", null)
	 );
	 }

	 @Test
	 public void testInsertWhere() throws Exception {
	 // SQL.Insert("USER").Values("NAME", "admin").Where(""); // 将抛出异常
	 }

	 @Test
	 public void testDelete() throws Exception {
	 print(
	 SQL.Delete("USER").Where("ID in ?", Arrays.asList(1, 2, 3, 4, 5))
	 );
	 }
	}

	

	

	

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.List;
	import java.util.Map;

	/**
	* 生成 Command 的帮助类
	*
	* @author yiding.he
	*/
	public class SQL {

	 private static boolean isEmpty(Object obj) {
	 if (obj == null) {
	 return true;
	 }

	 String str = obj.toString();
	 return str.length() == 0 || str.trim().length() == 0;
	 }

	 /////////////////////////////////////////////////////////

	 public static Select Select(String columns) {
	 return new Select(columns);
	 }

	 public static Update Update(String table) {
	 return new Update(table);
	 }

	 public static Insert Insert(String table) {
	 return new Insert(table);
	 }

	 public static Delete Delete(String table) {
	 return new Delete(table);
	 }

	 /////////////////////////////////////////////////////////

	 public static enum Pref {
	 AND, OR
	 }

	 public static class Pair {

	 private Pref pref = null;

	 private String name;

	 private Object value;

	 public Pair(String name, Object value) {
	 this.name = name;
	 this.value = value;
	 }

	 public Pair(Pref pref, String name, Object value) {
	 this.pref = pref;
	 this.name = name;
	 this.value = value;
	 }
	 }

	 public static class StatementPair extends Pair {

	 public StatementPair(String statement) {
	 super(statement, null);
	 }

	 public StatementPair(Pref pref, String statement) {
	 super(pref, statement, null);
	 }
	 }

	 /////////////////////////////////////////////////////////

	 @SuppressWarnings("unchecked")
	 public static abstract class Generatable<T extends Generatable> {

	 protected String table;

	 protected String statement;

	 protected List<Object> params = new ArrayList<Object>();

	 protected List<Pair> conditions = new ArrayList<Pair>();

	 public abstract Command toCommand();

	 protected String joinNames(List<Pair> pairs) {
	 if (pairs.isEmpty()) {
	 return "";
	 } else {
	 String result = "";
	 for (Pair pair : pairs) {
	 result += pair.name + ",";
	 }
	 result = result.substring(0, result.length() - 1);
	 return result;
	 }
	 }

	 protected String joinQuestionMarks(List<Pair> pairs) {
	 StringBuilder s = new StringBuilder();
	 for (int size = pairs.size(), i = 0; i < size; i++) {
	 s.append("?").append(i == size - 1 ? "" : ",");
	 }
	 return s.toString();
	 }

	 protected List<Object> joinValues(List<Pair> pairs) {
	 if (pairs.isEmpty()) {
	 return Collections.emptyList();
	 }

	 List<Object> result = new ArrayList<Object>();
	 for (Pair pair : pairs) {
	 result.add(pair.value);
	 }

	 return result;
	 }

	 public T Where(String statement) {
	 if (this instanceof Insert) {
	 throw new IllegalStateException("cannot use 'where' block in Insert");
	 }
	 this.conditions.add(new StatementPair(statement));
	 return (T) this;
	 }

	 public T Where(String column, Object value) {
	 if (this instanceof Insert) {
	 throw new IllegalStateException("cannot use 'where' block in Insert");
	 }
	 this.conditions.add(new Pair(column, value));
	 return (T) this;
	 }

	 public T Where(boolean exp, String statement) {
	 if (this instanceof Insert) {
	 throw new IllegalStateException("cannot use 'where' block in Insert");
	 }
	 if (exp) {
	 this.conditions.add(new StatementPair(statement));
	 }
	 return (T) this;
	 }

	 public T Where(boolean exp, String column, Object value) {
	 if (this instanceof Insert) {
	 throw new IllegalStateException("cannot use 'where' block in Insert");
	 }
	 if (exp) {
	 this.conditions.add(new Pair(column, value));
	 }
	 return (T) this;
	 }

	 public T And(String statement) {
	 this.conditions.add(new StatementPair(Pref.AND, statement));
	 return (T) this;
	 }

	 public T And(String column, Object value) {
	 this.conditions.add(new Pair(Pref.AND, column, value));
	 return (T) this;
	 }

	 public T And(boolean exp, String statement) {
	 if (exp) {
	 this.conditions.add(new StatementPair(Pref.AND, statement));
	 }
	 return (T) this;
	 }

	 public T And(boolean exp, String column, Object value) {
	 if (exp) {
	 this.conditions.add(new Pair(Pref.AND, column, value));
	 }
	 return (T) this;
	 }

	 public T AndIfNotEmpty(String column, Object value) {
	 return And(!isEmpty(value), column, value);
	 }

	 public T Or(String statement) {
	 this.conditions.add(new StatementPair(Pref.OR, statement));
	 return (T) this;
	 }

	 public T Or(String column, Object value) {
	 this.conditions.add(new Pair(Pref.OR, column, value));
	 return (T) this;
	 }

	 public T Or(boolean exp, String statement) {
	 if (exp) {
	 this.conditions.add(new StatementPair(Pref.OR, statement));
	 }
	 return (T) this;
	 }

	 public T Or(boolean exp, String column, Object value) {
	 if (exp) {
	 this.conditions.add(new Pair(Pref.OR, column, value));
	 }
	 return (T) this;
	 }

	 public T OrIfNotEmpty(String column, Object value) {
	 return Or(!isEmpty(value), column, value);
	 }

	 public T Append(String statement) {
	 this.conditions.add(new StatementPair(statement));
	 return (T) this;
	 }

	 public T Append(String column, Object value) {
	 this.conditions.add(new Pair(column, value));
	 return (T) this;
	 }

	 public T Append(boolean exp, String statement) {
	 if (exp) {
	 this.conditions.add(new StatementPair(statement));
	 }
	 return (T) this;
	 }

	 public T Append(boolean exp, String column, Object value) {
	 if (exp) {
	 this.conditions.add(new Pair(column, value));
	 }
	 return (T) this;
	 }

	 protected String generateWhereBlock() {
	 String where = "";

	 if (!this.conditions.isEmpty()) {
	 where = "where ";

	 for (int i = 0, conditionsSize = conditions.size(); i < conditionsSize; i++) {
	 Pair condition = conditions.get(i);
	 where = processCondition(i, where, condition);
	 }

	 }

	 return " " + where;
	 }

	 private String processCondition(int index, String where, Pair condition) {

	 where = where.trim();

	 // 第一个条件不能加 and 和 or 前缀
	 if (index > 0 && !where.endsWith("(")) {
	 if (condition.pref == Pref.AND) {
	 where += " and ";
	 } else if (condition.pref == Pref.OR) {
	 where += " or ";
	 }
	 }

	 where += " ";

	 if (condition instanceof StatementPair) { // 不带参数的条件
	 where += condition.name;

	 } else if (condition.value instanceof List) { // 参数为 List 的条件（即 in 条件）
	 String marks = "(";

	 for (Object o : (List) condition.value) {
	 marks += "?,";
	 this.params.add(o);
	 }

	 if (marks.endsWith(",")) {
	 marks = marks.substring(0, marks.length() - 1);
	 }
	 marks += ")"; // marks = "(?,?,?,...,?)"

	 where += condition.name.replace("?", marks); // "A in ?" -> "A in (?,?,?)"

	 } else {
	 where += condition.name;
	 this.params.add(condition.value);
	 }

	 return where;
	 }
	 }

	 /////////////////////////////////////////////////////////

	 public static class Insert extends Generatable<Insert> {

	 private String table;

	 private List<Pair> pairs = new ArrayList<Pair>();

	 public Insert(String table) {
	 this.table = table;
	 }

	 public Insert Values(String column, Object value) {
	 if (value != null) {
	 pairs.add(new Pair(column, value));
	 }
	 return this;
	 }

	 public Insert Values(boolean ifTrue, String column, Object value) {
	 if (ifTrue) {
	 Values(column, value);
	 }
	 return this;
	 }

	 public Insert Values(Map<String, Object> map) {
	 for (Map.Entry<String, Object> entry : map.entrySet()) {
	 Values(entry.getKey(), entry.getValue());
	 }
	 return this;
	 }

	 @Override
	 public Command toCommand() {
	 this.statement = "insert into " + table + "(" + joinNames(pairs) + ") values (" + joinQuestionMarks(pairs) + ")";
	 this.params = joinValues(pairs);

	 return new Command(statement, params);
	 }
	 }

	 /////////////////////////////////////////////////////////

	 /**
	 * 用于生成 update 语句的帮助类
	 */
	 public static class Update extends Generatable<Update> {

	 private List<Pair> updates = new ArrayList<Pair>();

	 public Update(String table) {
	 this.table = table;
	 }

	 @Override
	 public Command toCommand() {
	 this.statement = "update " + table +
	 " set " + generateSetBlock() + " " + generateWhereBlock();

	 return new Command(this.statement, this.params);
	 }

	 private String generateSetBlock() {
	 String statement = "";

	 for (int i = 0, updatesSize = updates.size(); i < updatesSize; i++) {
	 Pair pair = updates.get(i);
	 if (pair instanceof StatementPair) {
	 statement += pair.name;
	 } else {
	 this.params.add(pair.value);
	 statement += pair.name + "=?";
	 }

	 if (i < updatesSize - 1) {
	 statement += ",";
	 }
	 }

	 return statement;
	 }

	 public Update Set(boolean exp, String column, Object value) {
	 if (exp) {
	 this.updates.add(new Pair(column, value));
	 }
	 return this;
	 }

	 public Update Set(String column, Object value) {
	 this.updates.add(new Pair(column, value));
	 return this;
	 }

	 public Update Set(String setStatement) {
	 this.updates.add(new StatementPair(setStatement));
	 return this;
	 }

	 public Update Set(boolean exp, String setStatement) {
	 if (exp) {
	 this.updates.add(new StatementPair(setStatement));
	 }
	 return this;
	 }

	 public Update SetIfNotNull(String column, Object value) {
	 return Set(value != null, column, value);
	 }

	 public Update SetIfNotEmpty(String column, Object value) {
	 return Set(!isEmpty(value), column, value);
	 }
	 }

	 /////////////////////////////////////////////////////////

	 /**
	 * 用于生成 select 语句的帮助类
	 */
	 public static class Select extends Generatable<Select> {

	 private String columns;

	 private String from;

	 private String orderBy;

	 private String groupBy;

	 public Select(String columns) {
	 this.columns = columns;
	 }

	 public Select From(String from) {
	 this.from = from;
	 return this;
	 }

	 public Select OrderBy(String orderBy) {
	 this.orderBy = orderBy;
	 return this;
	 }

	 public Select GroupBy(String groupBy) {
	 this.groupBy = groupBy;
	 return this;
	 }

	 @Override
	 public Command toCommand() {
	 this.statement = "select " + this.columns + " from " + this.from + " ";

	 this.statement += generateWhereBlock();

	 if (!isEmpty(this.groupBy)) {
	 this.statement += " group by " + this.groupBy;
	 }

	 if (!isEmpty(this.orderBy)) {
	 this.statement += " order by " + this.orderBy;
	 }

	 return new Command(this.statement, this.params);
	 }

	 }

	 /////////////////////////////////////////////////////////

	 public static class Delete extends Generatable<Delete> {

	 public Delete(String table) {
	 this.table = table;
	 }

	 @Override
	 public Command toCommand() {
	 this.statement = "delete from " + table + generateWhereBlock();
	 return new Command(this.statement, this.params);
	 }
	 }

	}

	

	

	import java.util.List;

	/**
	* 表示 SQL 命令的类。其中包含 SQL 语句和参数两个部分。参数的值要和 SQL 语句中的问号一一对应。
	*/
	public class Command {

	 private String statement;

	 private List params;

	 private List paramTypes;

	 /**
	 * 缺省构造函数
	 */
	 public Command() {
	 }

	 /**
	 * 构造函数
	 *
	 * @param statement SQL 语句
	 * @param params 参数
	 */
	 public Command(String statement, List params) {
	 this.statement = statement;
	 this.params = params;
	 }

	 public Command(String statement, List params, List paramTypes) {
	 this.statement = statement;
	 this.params = params;
	 this.paramTypes = paramTypes;
	 }

	 public List getParamTypes() {
	 return paramTypes;
	 }

	 public void setParamTypes(List paramTypes) {
	 this.paramTypes = paramTypes;
	 }

	 /**
	 * 获得 SQL 语句
	 *
	 * @return SQL 语句
	 */
	 public String getStatement() {
	 return statement;
	 }

	 /**
	 * 设置 SQL 语句
	 *
	 * @param statement SQL 语句
	 */
	 public void setStatement(String statement) {
	 this.statement = statement;
	 }

	 /**
	 * 获得参数
	 *
	 * @return 参数
	 */
	 public List getParams() {
	 return params;
	 }

	 /**
	 * 设置参数
	 *
	 * @param params 参数
	 */
	 public void setParams(List params) {
	 this.params = params;
	 }

	 @Override
	 public String toString() {
	 return "Command{" +
	 "statement='" + statement + '\'' +
	 ", params=" + params +
	 '}';
	 }
	}
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