The aggregate functions array_agg and xmlagg , as well as similar user-defined aggregate functions , produce meaningfully different result values depending on the order of the input values. PostgreSQL using a sequential scan of the entire table. Below is a description of each table. The function does not add the separator at the end of the string. This ordering is unspecified by default, but can be controlled by writing an ORDER BY.
Postgresql array_agg of multiple columns with JDBC. Sorting in array_agg function. Sort a text aggregate created with array_agg in. This article is half-done without your Comment! You can get distinct values for each column using array _ agg ().
Note that in Oracle 11G Release Oracle introduced an aggregate function call LISTAGG which is similar. Neste repeated fields are very powerful, but the SQL required to query them looks a bit unfamiliar. GitHub is home to over million developers working together to host and review code, manage projects, and build software together. You can apply the window function row_number() to remember the order of elements. Most developers do this by running a query to get much of the raw data, looping over the data and pushing it into a set, appending each new value to the appropriate key.
ARRAY and not the plain types.