![]() The main limitation of the single-parameter form of crosstab is that it treats all values in a group alike, inserting each value into the first available column. Notice that crosstab itself does not pay any attention to the second column of the query result it’s just there to be ordered by, to control the order in which the third-column values appear across the page.ģ) crosstab(text source_sql, text category_sql) Note: In practice the SQL query should always specify ORDER BY 1,2 to ensure that the input rows are properly ordered, that is, values with the same row_name are brought together and correctly ordered within the row. Select * from crosstab2(‘select rowid, attribute, valueīy using this function there is no need to specify row_name and number of column_name in sql. If there are fewer rows in a group than there are output value columns, the extra output columns are filled with nulls if there are more rows, the extra input rows are skipped. It fills the output value columns, left to right, with the value fields from these rows. The crosstab function produces one output row for each consecutive group of input rows with the same row_name value. ![]() The names of the output columns are up to you. You can set up as many output value columns as you wish. The FROM clause must define the output as one row_name column (of the same data type as the first result column of the SQL query) followed by N value columns (all of the same data type as the third result column of the SQL query). Order by 1,2’) as ct(row_name text, category_1 text, category_2 text) Select * from crosstab(‘select rowid, attribute, value Since the number of value columns is always With the value columns specified by a second query ![]() crosstab2, crosstab3, and crosstab4 are predefined, but you canĬreate additional crosstab N functions as described Here is different syntax to use crosstab in postgres FunctionĬontaining row names plus N value columns, where N is determined by the row typeĬontaining row names plus N value columns. (1546560000, 187923, 1.The crosstab function is used to produce “pivot” displays, wherein data is listed across the page rather than down. Alternatively, make sure the crosstab SQL returns the desired type explicitly, e.g.:.Adapt the outer type to a variable numeric type, e.g.In this case, they must match or at least the crosstab column type definitions must be able to completely contain the types as returned by the crosstab function SQL. PostgreSQL can be quite picky and doesn't auto-magically convert them in many cases. ![]() Then, you need to be careful about the data types. Initialize the module tablefunc: CREATE EXTENSION tablefunc Although you didn't mention which error you are getting, this is how to make it work:
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