mybatis-plus 使用Condition拼接Sql语句各方法的使用

1.setSqlSelect—用于添加查询的列信息

public Wrapper<T> setSqlSelect(String... columns) {
        StringBuilder builder = new StringBuilder();
        String[] arr = columns;
        int len = columns.length;

        for(int i = 0; i$ < len; ++i$) {
            String column = arr$[i$];
            if (StringUtils.isNotEmpty(column)) {
                if (builder.length() > 0) {
                    builder.append(",");
                }

                builder.append(column);
            }
        }

        this.sqlSelect = builder.toString();
        return this;
    }

2.eq—拼接等于的where语句 column=params

public Wrapper<T> eq(boolean condition, String column, Object params) {
        if (condition) {
            this.sql.WHERE(this.formatSql(String.format("%s = {0}", column), params));
        }

        return this;
    }

3.ne—拼接不等于的where语句 column<>params

public Wrapper<T> ne(boolean condition, String column, Object params) {
        if (condition) {
            this.sql.WHERE(this.formatSql(String.format("%s <> {0}", column), params));
        }

        return this;
    }

4.allEq–拼接数据以map封装的等于的where语句

 public Wrapper<T> allEq(boolean condition, Map<String, Object> params) {
        if (condition && MapUtils.isNotEmpty(params)) {
            Iterator iterator = params.entrySet().iterator();

            while(iterator.hasNext()) {
                Entry<String, Object> entry = (Entry)iterator.next();
                Object value = entry.getValue();
                if (StringUtils.checkValNotNull(value)) {
                    this.sql.WHERE(this.formatSql(String.format("%s = {0}", entry.getKey()), entry.getValue()));
                }
            }
        }

        return this;
    }

5.gt—-拼接大于号的where语句

public Wrapper<T> gt(boolean condition, String column, Object params) {
        if (condition) {
            this.sql.WHERE(this.formatSql(String.format("%s > {0}", column), params));
        }

        return this;
    }

6.ge–拼接大于等于号的where语句 （代码类似5）
7.lt—拼接小于号的where语句
8.le—小于等于

    /**
         *
         AND (user_name=#{ew.paramNameValuePairs.MPGENVAL1} AND id=1)
         OR (user_status=#{ew.paramNameValuePairs.MPGENVAL2} OR status=1
         AND user_nickname NOT LIKE #{ew.paramNameValuePairs.MPGENVAL3})
         AND (new=xx AND hhh LIKE #{ew.paramNameValuePairs.MPGENVAL4})
         AND (pwd=11 AND n1 IS NOT NULL AND n2 IS NOT NULL AND n3 IS NULL)
         GROUP BY x1, x2,x3
         HAVING (x1=11 AND x3=433)
         ORDER BY dd, d1,d2
         */
        ew.where("user_name={0}", "'zhangsan'").and("id=1")
                .orNew("user_status={0}", "0").or("status=1")
                .notLike("user_nickname", "notvalue")
                .andNew("new=xx").like("hhh", "ddd")
                .andNew("pwd=11").isNotNull("n1,n2").isNull("n3")
                .groupBy("x1").groupBy("x2,x3")
                .having("x1=11").having("x3=433")
                .orderBy("dd").orderBy("d1,d2");

9.and — 在没有出现下一个andNew或者orNew之前的所有where条件在一个括号里
10.andNew –新建一组and语句
11.or,orNew–同上

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转自：https://blog.csdn.net/qq_36752632/article/details/79035980