Teach jsonpath string() to unwrap in lax mode

This was an ommission in commit 66ea94e, and brings it into compliance
with both other methods and the standard.

Per complaint from David Wheeler.

Author: David Wheeler, Jeevan Chalke
Reviewed-by: Chapman Flack
Discussion: https://postgr.es/m/A64AE04F-4410-42B7-A141-7A7349260F4D@justatheory.com

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 17c44bc33846449a311b97f807852b5fe659278b..2609269610b27e60876b9386442f1fa2036210ed 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -17792,7 +17792,10 @@ ERROR:  jsonpath member accessor can only be applied to an object
     methods available in <type>jsonpath</type>.  Note that while the unary
     operators and methods can be applied to multiple values resulting from a
     preceding path step, the binary operators (addition etc.) can only be
-    applied to single values.
+    applied to single values.  In lax mode, methods applied to an array will be
+    executed for each value in the array.  The exceptions are
+    <literal>.type()</literal> and <literal>.size()</literal>, which apply to
+    the array itself.
    </para>
 
    <table id="functions-sqljson-op-table">

diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index ceb30033e1c6632b716209876a9c6a16570afd86..c30d059a7627292a6cf2cc9e2985efea24e3721a 100644 (file)
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -1606,6 +1606,9 @@ executeItemOptUnwrapTarget(JsonPathExecContext *cxt, JsonPathItem *jsp,
                JsonbValue  jbv;
                char       *tmp = NULL;
 
+               if (unwrap && JsonbType(jb) == jbvArray)
+                   return executeItemUnwrapTargetArray(cxt, jsp, jb, found, false);
+
                switch (JsonbType(jb))
                {
                    case jbvString:

diff --git a/src/test/regress/expected/jsonb_jsonpath.out b/src/test/regress/expected/jsonb_jsonpath.out
index c3f8e8249dbfe6939b0a305f869a172485d07a7d..a6112e86fa7ae17f725516f2e89f5ec24b8ec2e2 100644 (file)
--- a/src/test/regress/expected/jsonb_jsonpath.out
+++ b/src/test/regress/expected/jsonb_jsonpath.out
@@ -2525,7 +2525,10 @@ select jsonb_path_query('null', '$.string()', silent => true);
 (0 rows)
 
 select jsonb_path_query('[]', '$.string()');
-ERROR:  jsonpath item method .string() can only be applied to a bool, string, numeric, or datetime value
+ jsonb_path_query 
+------------------
+(0 rows)
+
 select jsonb_path_query('[]', 'strict $.string()');
 ERROR:  jsonpath item method .string() can only be applied to a bool, string, numeric, or datetime value
 select jsonb_path_query('{}', '$.string()');
@@ -2576,6 +2579,13 @@ select jsonb_path_query('1234', '$.string().type()');
  "string"
 (1 row)
 
+select jsonb_path_query('[2, true]', '$.string()');
+ jsonb_path_query 
+------------------
+ "2"
+ "true"
+(2 rows)
+
 select jsonb_path_query('"2023-08-15 12:34:56 +5:30"', '$.timestamp().string()');
 ERROR:  cannot convert value from timestamptz to timestamp without time zone usage
 HINT:  Use *_tz() function for time zone support.

diff --git a/src/test/regress/sql/jsonb_jsonpath.sql b/src/test/regress/sql/jsonb_jsonpath.sql
index cbd2db533d40f015cedcd0bf9c03826fb9c78d61..5e14f7759bb64cc51d3acbf7798ed3be968f60d5 100644 (file)
--- a/src/test/regress/sql/jsonb_jsonpath.sql
+++ b/src/test/regress/sql/jsonb_jsonpath.sql
@@ -586,6 +586,7 @@ select jsonb_path_query('"1.23aaa"', '$.string()');
 select jsonb_path_query('1234', '$.string()');
 select jsonb_path_query('true', '$.string()');
 select jsonb_path_query('1234', '$.string().type()');
+select jsonb_path_query('[2, true]', '$.string()');
 select jsonb_path_query('"2023-08-15 12:34:56 +5:30"', '$.timestamp().string()');
 select jsonb_path_query_tz('"2023-08-15 12:34:56 +5:30"', '$.timestamp().string()'); -- should work
 select jsonb_path_query_array('[1.23, "yes", false]', '$[*].string()');