From: Tom Lane <tgl@sss.pgh.pa.us>
To: Wells Oliver <wells.oliver@gmail.com>
Cc: pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: Casting json (or jsonb) to real
Date: Tue, 31 May 2022 20:50:51 -0400
Message-ID: <378261.1654044651@sss.pgh.pa.us> (raw)
In-Reply-To: <CAOC+FBW85OU9bRFC0ozNtiWFcGkMjCLv3fuVH8LSbiZ8qcX8_g@mail.gmail.com>
References: <CAOC+FBW85OU9bRFC0ozNtiWFcGkMjCLv3fuVH8LSbiZ8qcX8_g@mail.gmail.com>
Wells Oliver <wells.oliver@gmail.com> writes:
> When I know this value is a floating point value I would just like to cast
> SELECT value::real but you can't do that. You can do SELECT
> (jsonbcol->>'somekey')::real, but these columns just store a value.
Works for me, in v11 and up:
regression=# select '1.4531'::jsonb::real;
float4
--------
1.4531
(1 row)
In older versions you could do
regression=# select '1.4531'::jsonb::text::real;
float4
--------
1.4531
(1 row)
I fear that either one involves a conversion to text and back
under the hood :-(. Now, if you were casting to numeric,
that would be very cheap.
regards, tom lane
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To: pgsql-admin@postgresql.org
Cc: tgl@sss.pgh.pa.us, wells.oliver@gmail.com
Subject: Re: Casting json (or jsonb) to real
In-Reply-To: <378261.1654044651@sss.pgh.pa.us>
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