up vote 14 down vote favorite 1 How do you check if json field in postgres has element? I have tried with json->>attribute is not null and doesnt work.RecommendAdd Column If Not Exists in Postgresql. 22 Responses to Postgres Column name Does Not Exist.If I add an column in my first table in my database in postgresql, error message is : column not found if I delete all columns ,error message is : syntax error at or near FROM (what I do is just execute a sql statement:select from ). I have recently cloned a project to my local Ubuntu box now that I am remote, and upon rake db migrate, I get the following error: PG::UndefinedObject: ERROR: type " json" does not exist. A couple columns in my tables that are The following bug has been logged on the website: Bug reference: 13833 Logged by: Michael Milton Email address: [hidden email] PostgreSQLstackoverflow.com/questions/34472961/postgres-order-by-value-inside-json -causes-column-does-not-exist-error. For PostgreSQL a mutable dictionary recipe exists: httpBecause as of Postgres 9.4, theres no way to selectively update JSON fields. You have to update the entire column.So yes, absolutely this does apply to Postgres and JSONand Python. Note that "sets" is a json column with perfectly valid data. Now all I want to do is sort the output by a value the "sets" columnThis may not be relevant, but if I dont use any json operators at all, and try to just sort by "sets" (not that that will work), Postgres at least acknowledges that the column exists The important part is that if you want to order by an arbitrary expression, you can only use input- column values in it. > The summary of it is that this query throws the error " column sets does not > exist", despite the fact that it is created in the SELECT clause Setting the column to NULL if the corresponding json field does not exist is fine. FOR roow IN SELECT columnname FROM informationschema.columns. Or query informationschema.routines.
foo::regproc, regproc -foo (1 row) postgres select foox::regproc, ERROR: function "foox" blakmatrix changed the title from PostgreSQL: operator does not exist: text text findOrCreat on JSON data type to PostgreSQL: operatorThis is the desired behaviour :). We know nothing about the structure of the json in the column, so we asume that country is an array. To do an in query you The first thing was to convert the TEXT column to a JSON column.Which does not use the index we created at all, but instead does a table scan on paypalorders looking for your value.Knowing that postgres is pretty picky about how the index is generated, I decided to drop the existing index PostgreSQL offers a JSON column type, but how do you migrate existing data into a JSON-based structure? We recently had a case where we wanted to migrate some data in an existing table from a fixed set of columns into a more flexible JSON column. Note that "sets" is a json column with perfectly valid data. Now all I want to do is sort the output by a value the "sets" columnThis may not be relevant, but if I dont use any json operators at all, and try to just sort by "sets" (not that that will work), Postgres at least acknowledges that the column exists PostgreSQL 9.3 and later versions support JSON, so you can store JSON data and use native Postgres functions to operate on it.Right now, well simply begin with an example that creates and populates a table (country) with a JSON column (extrainfo). Exists quite a long time not, way longer before the term NoSQL was coined hstore support since 2003 JSON support since 2006, since 9.2 part of the Postgres core.If the entry does not exist in the left hand operator it is added, otherwise the value gets overwritten. Modify hstore column. Location: Salzburg, Salzburg, Austria. Error for Querying JSON in Postgres: function jsonextractIf IF EXISTS is specified and the column does not exist , no error is thrown. You can only use SET NOT NULL when the column contains no null values.