String to numeric. Stephan Szabo It's more complicated than that (and postgres does some of this but not all), for example the cast text->float8->numeric potentially loses precision and should probably not be an automatic cast for that reason. Note: In PostgreSQL, the Numeric data type can have a value of up to 131,072 digits before the decimal point of 16,383 digits after the decimal point. There are two ways to typecast in Postgres: You either do it the SQL standard way: select cast(3.141593 as bigint); or you could use the Postgres-specific cast operator: :: select (3.141593 :: bigint); You might also want to consider the various rounding functions. In case of processor memory, the double precision types can occupy up to 64 bit of memory. select cast(109.652 as decimal(4,1)); numeric ----- 109.7 In this example, the PRICEPAID column (a DECIMAL(8,2) column) in the SALES table is converted to a DECIMAL(38,2) column and the values are multiplied by 100000000000000000000. Curiosily the "NULL to SqlType" not works, "ERROR: cannot cast jsonb null to type integer". SELECT '123456.78'::float8::numeric::money; Result: $123,456.78 PostgreSQL provides the DOUBLE PRECISION data type for this kind of numeric data– the data type offers … It is recommended against using floating point numbers to handle money due to the potential for rounding errors. When converting from double precision, it is quite similar to rounding off the expression. The function code itself is responsible for what it returns. boolean→boolean, number→numeric, number→int, number→bigint; number→flloat, number→double. Numeric plain only shows numbers after the decimal point that are being used. Text and characters. However, if you must do it, you can convert to numeric first, then to money. In this number, the precision is 6, and the scale is 2.. RETURNS TABLE(m numeric(20,10), n numeric(20,10)) does not enforce the data types of the returned columns; it's simply a declaration, metadata intended to inform the callers what the function should return. The declaration cannot not require anything, it's a "promise" that is to be fulfilled by the function implementation. Postgresql cast double precision to numeric. Why not optimized for NULL? I'm using 8.2.4 Numeric with scale precision always shows the trailing zeros. 2) precision The precision argument is an integer that indicates the number of decimal places. SELECT cast(123456.78 as money); Result: $123,456.78 Convert from a Floating Point Number. tham "binary JSONb → string → binary SQL"? Double precision expression takes more decimal points when compared to float data types. The to_date function in PostgreSQL is used to converting strings into CAST( number AS double precision) or alternatively number::double Can't convert to Date – BWhite Aug 30 '19 at 23:30 what version of postgres? We can understand the concept of precision and scale by seeing in the following example: Suppose we have the number 2356.78. It is safe for money values to cast to and from the numeric type (used for arbitrary precision, as shown above), so it is recommended to always use numeric as an intermediary before performing converting to other types. I would like to have the data in my table with scale and precision, but my views to be cast to numeric without any scale or precision. Apache Derby and PostgreSQL - Criteria selectCase with Enu as you can see it worked for me (click the "here" in the answer) that s a live demo. For example, what wold be faster (?) Timestamps in PostgreSQL. However, when I cast a numeric(16,4) to a ::numeric it doesn't cast it. 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