SELECT name, round(gdp/(population*1000),0)*1000 as 'per-capita GDP' FROM world WHERE gdp >= 1000000000000; 11.Greece has capital Athens. Each of the strings 'Greece', and 'Athens' has 6 characters. Show the name and capital where the name and the capital have the same number of ch...
Capabilities of theSELECTStatement(SELECT语句的功能) Data retrieval from data base is done through appropriate and efficient use of SQL. Three concepts from relational theory encompass the capability of the SELECT statement: projection, selection, and joining. Projection(投影): A project operation sele...
selectsubstring(c,2,charindex(',',c,2)-2)asempnofrom ( selectsubstring(csv.emps,iter.pos,len(csv.emps))ascfrom ( select','+@strings+','asemps ) csv, ( --select id as pos from t100 --生产1-10000的结果集 Selecta+b*10+c*100+d*1000+1asposFrom (Select0AsaUnionSelect1UnionSelect...
hive> select1 from test_table where '123456aa' rlike '^\\d+$'; 11. REGEXP操作: REGEXP 语法: A REGEXP B 操作类型: strings 描述: 功能与RLIKE相同 举例: hive> select1 from test_table where 'footbar' REGEXP '^f.*r$'; 二、数学运算:1. 加法操作: + 语法: A + B 操作类型:所有...
( $conn === false ) { echo "Could not connect.\n"; die( print_r( sqlsrv_errors(), true)); } /* Set up the Transact-SQL query. */ $tsql = "SELECT ReviewerName, CONVERT(varchar(32), ReviewDate, 107) AS [ReviewDate], Rating, Comments FROM Production.ProductReview WHERE ...
select t1.*,substr(t1.phone,1,3) as area_number from temp as t1 idnameemailphonearea_number 1 John Doe john.doe@example.com 123-456-7890 123 2 Jane Smith jane.smith@example.com 555-555-5555 555 3 Bob Johnson bob.johnson@example.com 555-123-4567 555 4 Alice Brown alice.brown@exa...
2. from_unixtime:将时间戳转为日期格式 select from_unixtime(1603843200); 3. current_date:当前日期 select current_date; 4. current_timestamp:当前的日期加时间 select current_timestamp; 5. to_date:抽取日期部分 select to_date('2020-10-28 12:12:12'); ...
hive -S -e 'select table_cloum from table' -S,终端上的输出不会有mapreduce的进度,执行完毕,只会把查询结果输出到终端上。
columns : list, default: None List of column names to select from SQL table (only used when reading a table). chunksize : int, default None If specified, return an iterator where chunksize is the number of rows to include in each chunk. 上述为官网文档参数说明:Pandas.read_sql() 首先我们...
//查询年龄最大的前两名val result=sparkSession.sql("select * from person order by age desc limit 2")//保存结果为json文件。注意:如果不指定存储格式,则默认存储为parquetresult.write.format("json").save("hdfs://ip:port/res2") 3.说说Spark SQL的几种使用方式 ...