![]() The user can create a pivot table in PostgreSQL using either the crosstab function which is provided by the tablefunc or using the CASE statement. ![]() Pivot tables are created to transform the data from the rows to the columns and it can be used to get the results according to a particular column in the table. How to Create A Pivot Table in PostgreSQL This guide explains the process of creating a Pivot table in PostgreSQL. The user can create pivot tables in PostgreSQL to convert data in the rows with the columns data. It allows the user to query these tables and fetch data according to the user’s requirements and gain useful insights through that information. should be dynamic also.PostgreSQL enables the user to create tables in the relational database to store data in them using SQL queries. Notice that I used VALUES for the second argument instead of SELECT DISTINCT, it is a better approach if you are sure these will be the only available values, if it is not static, then the AS t_pivot. You don't need to worry with the first column, it is actually useless for you, so we can just remove it: SELECT day,hour,name,cause_0,cause_1 FROM (SELECT * from crosstab (ĪS t_pivot (row_name text, day date, hour int, name integer, cause_0 integer,cause_1 integer)) AS t This will give a result like this: row_name | day | hour | name | cause_0 | cause_1 'select row(day,hour,name),day, hour, name, cause, sum(c_p) as c_pĪS t_pivot (row_name text, day date, hour int, name integer, cause_0 integer,cause_1 integer) I'm not sure if it is the best approach, but I used the row constructor to do that (so we don't need to care about data types): SELECT * from crosstab ( So, for your case you must get these three columns and represent them as only one. ![]() But crosstab also allow extra columns, that it doesn't treat it as special, it just add it to the result. Seems that crosstab function expect only one column to hold the row identification, and, if I got that right, you have 3 columns: day, name and hour. Query's output matches the specified output column order. However, ordering of the categories within a group is not important.Īlso, it is essential to be sure that the order of the category_sql ![]() In practice the source_sql query should always specify ORDER BY 1 toĮnsure that values with the same row_name are brought together. To be the same for all rows with the same row_name value. Any columns between row_nameĪnd category are treated as "extra". The category and value columns mustīe the last two columns, in that order. It may also have one or more "extra" columns. This statement must return one row_name column, one category column,Īnd one value column. Source_sql is a SQL statement that produces the source set of data. 'select distinct cause from t order by 1')ĪS t_pivot (hour integer, date timestamp, name integer, cause_0 integer,cause_1 integer) 'select hour, date, name, cause, sum(c_p) as c_p Update This one works (hour used as a row_name, date and name are extra columns): SELECT * from crosstab ( I think it's easier to maintain and read it in the future (but this is subjective opinion). Sum(case when cause = 1 then c_p else 0 end) cause_1 Sum(case when cause = 0 then c_p else 0 end) cause_0, ![]() I haven't used crosstab function and can't test it now (there's no tablefunc extension on sqlfiddle), but in general I'd prefer simple SQL if I need such a pivot: select ![]()
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