返回2的x次方

使用示例

import com.youngdatafan.sqlbuilder.enums.DatabaseType;
import com.youngdatafan.sqlbuilder.enums.FunctionType;
import com.youngdatafan.sqlbuilder.model.Function;
import com.youngdatafan.sqlbuilder.model.Model;
import com.youngdatafan.sqlbuilder.model.Query;
import com.youngdatafan.sqlbuilder.model.Schema;
import com.youngdatafan.sqlbuilder.model.Table;

public class Test {

    @org.junit.Test
    public void getFunction() {
        Schema schema = Schema.getSchema("");
        Table test = Table.getOriginalTable(schema, "test", "t");
        Model num = test.addField("num");
        Query query = new Query();
        Function function = Function.getFunction(FunctionType.EXP2, num);
        query.addColumn("val", function);
        query.addFrom(test);
        System.out.println("oracle：");
        System.out.println(query.getDatabaseSql(DatabaseType.ORACLE));
        System.out.println();

        System.out.println("pg：");
        System.out.println(query.getDatabaseSql(DatabaseType.POSTGRESQL));
        System.out.println();

        System.out.println("clickhouse：");
        System.out.println(query.getDatabaseSql(DatabaseType.CLICKHOUSE));
        System.out.println();

        System.out.println("mysql：");
        System.out.println(query.getDatabaseSql(DatabaseType.MYSQL));
        System.out.println();

        System.out.println("sqlserver：");
        System.out.println(query.getDatabaseSql(DatabaseType.MSSQL));
        System.out.println();

        System.out.println("kdw：");
        System.out.println(query.getDatabaseSql(DatabaseType.KDW));
        System.out.println();
    }
}

根据数据源获取对于数据库的sql。

ORACLE

SELECT POWER(2, t."num") AS "val" FROM "test" t  

MYSQL

SELECT POW(2, t.`num`) AS `val` FROM `test` t  

POSTGRESQL

SELECT POW(2, t.num) AS val FROM test t 

CLICKHOUSE

SELECT POWER(2, t.num) AS val FROM test t  

KDW

SELECT POW(2, t.num) AS val FROM test t  

SQLSERVER

SELECT POWER(2, t.num) AS val FROM test t