diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/plpgsql.sgml | 15 | ||||
| -rw-r--r-- | doc/src/sgml/typeconv.sgml | 7 |
2 files changed, 12 insertions, 10 deletions
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index 69a0885f2aa..158d9d2f223 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -881,13 +881,14 @@ PREPARE <replaceable>statement_name</>(integer, integer) AS SELECT $1 < $2; <para> If the expression's result data type doesn't match the variable's - data type, or the variable has a specific size/precision - (like <type>char(20)</type>), the result value will be implicitly - converted by the <application>PL/pgSQL</application> interpreter using - the result type's output-function and - the variable type's input-function. Note that this could potentially - result in run-time errors generated by the input function, if the - string form of the result value is not acceptable to the input function. + data type, the value will be coerced as though by an assignment cast + (see <xref linkend="typeconv-query">). If no assignment cast is known + for the pair of data types involved, the <application>PL/pgSQL</> + interpreter will attempt to convert the result value textually, that is + by applying the result type's output function followed by the variable + type's input function. Note that this could result in run-time errors + generated by the input function, if the string form of the result value + is not acceptable to the input function. </para> <para> diff --git a/doc/src/sgml/typeconv.sgml b/doc/src/sgml/typeconv.sgml index ed377722884..c031c01ed35 100644 --- a/doc/src/sgml/typeconv.sgml +++ b/doc/src/sgml/typeconv.sgml @@ -844,9 +844,10 @@ Check for an exact match with the target. <step performance="required"> <para> -Otherwise, try to convert the expression to the target type. This will succeed -if there is a registered cast between the two types. -If the expression is an unknown-type literal, the contents of +Otherwise, try to convert the expression to the target type. This is possible +if an <firstterm>assignment cast</> between the two types is registered in the +<structname>pg_cast</> catalog (see <xref linkend="sql-createcast">). +Alternatively, if the expression is an unknown-type literal, the contents of the literal string will be fed to the input conversion routine for the target type. </para> |