SQL之聚合函数Aggregate Function 这里介绍SQL中的聚合函数Aggregate Function 概述 聚合函数是多对一函数。它们使用多个记录的值作为输入、计算、转换返回为单个值。聚合函数通常与GROUP BY子句一起使用,以对数据进行分组并对每个组下的若干条记录应用聚合函数。这样可以在一个查询中得到每个组汇总的统计结果。这里建立一...
DataStreamSource<String> source = env.socketTextStream("localhost", 8888); SingleOutputStreamOperator<Tuple3<String, Double, Double>> tpStream = source.map(new MapFunction<String, Tuple3<String, Double, Double>>() { @Override public Tuple3<String, Double, Double> map(String input) throws...
SQL Function Reference SQL - Date Functions SQL - String Functions SQL - Aggregate Functions SQL - Numeric Functions SQL - Text & Image Functions SQL - Statistical Functions SQL - Logical Functions SQL - Cursor Functions SQL - JSON Functions SQL - Conversion Functions SQL - Datatype Functions SQ...
aggregate functions return the same value each time that they are called, when called with a specific set of input values. SeeDeterministic and Nondeterministic Functionsfor more information about function determinism. TheOVER clausemay follow all aggregate functions, except the STRING_AGG, GROUPING or...
delimiter: A literal string to use as a separator between the concatenated values. Viewstring_aggquery example sum Returns the sum of all values in the specified column. sum(expression) Arguments expression: Expression to operate on. Can be a constant, column, or function, and any combination ...
This form of COUNT does not count NULL values for the column. Example 6.31 shows the use of the first form of the aggregate function COUNT. Example 6.31 Count all different jobs in each project: USE sample; SELECT project_no, COUNT(DISTINCT job) job_count FROM works_on GROUP BY project_...
Specify the data table and the field to be queried inSQL Statementby selecting them instead of entering their names. count(Expression): Returns the number of non-null values of theExpressionfield. You can use the following statement inSpark SQLto obtain the number of non-null values of theShi...
*/ private[flink] def createDataSetAggregateFunctions( generator: AggregationCodeGenerator, namedAggregates: Seq[CalcitePair[AggregateCall, String]], inputType: RelDataType, inputFieldTypeInfo: Seq[TypeInformation[_]], outputType: RelDataType, groupings: Array[Int], tableConfig: TableConfig): ( ...
Types of the aggregate function arguments. Example CREATETABLEt ( column1 AggregateFunction(uniq,UInt64), column2 AggregateFunction(anyIf,String,UInt8), column3 AggregateFunction(quantiles(0.5,0.9),UInt64) )ENGINE=... uniq, anyIf (any+If) andquantilesare the aggregate functions supported in Clic...
Applies to:Databricks SQLDatabricks Runtime 10.4 LTS and above Returns an array consisting of all values inexprwithin the group. This function is a synonym forcollect_listaggregate function. Syntax array_agg ( [ALL | DISTINCT] expr ) [FILTER ( WHERE cond ) ] ...