wasm/JS: documented DB.selectValue() and corrected the fetching of NULL columns via Stmt.get().

FossilOrigin-Name: 70f91fab825d365f505750acdb8d3ae532880c4cdb64d1e61bb21b24a115958b

ext/fiddle/sqlite3-api.js

@@ -736,11 +736,18 @@
             this._udfs[name] = pUdf;
             return this;
         }/*createFunction()*/,
+        /**
+           Prepares the given SQL, step()s it one time and returns the
+           value of the first result column. If it has no results,
+           undefined is returned. If passed a second argument, it is
+           treated like an argument to Stmt.bind(), so may be any type
+           supported by that function. Throws on error (e.g. malformed
+           SQL).
+        */
         selectValue: function(sql,bind){
             let stmt, rc;
             try {
-                stmt = this.prepare(sql);
-                stmt.bind(bind);
+                stmt = this.prepare(sql).bind(bind);
                 if(stmt.step()) rc = stmt.get(0);
             }finally{
                 if(stmt) stmt.finalize();
@@ -1155,6 +1162,7 @@
             switch(undefined===asType
                    ? S.sqlite3_column_type(this._pStmt, ndx)
                    : asType){
+                case S.SQLITE_NULL: return null;
                 case S.SQLITE_INTEGER:{
                     return 0 | S.sqlite3_column_double(this._pStmt, ndx);
                     /* ^^^^^^^^ strips any fractional part and handles

ext/fiddle/testing1.js

@@ -115,7 +115,9 @@ INSERT INTO t(a,b) VALUES(1,2),(3,4),(?,?);`,
             assert(3===db.selectValue("select bar(1,2)")).
             assert(-1===db.selectValue("select bar(1,2,-4)"));
 
-        T.assert('hi' === db.selectValue("select ?",'hi'));
+        T.assert('hi' === db.selectValue("select ?",'hi')).
+            assert(null===db.selectValue("select null"));
+                 
     }finally{
         db.close();
     }

manifest

@@ -1,5 +1,5 @@
-C wasm/JS:\sadded\ssupport\sfor\sscalar\sUDFs.\sFixed\sa\sdeallocation\sproblem\swith\sbind()ed\sstrings/blobs.
-D 2022-05-24T00:22:10.054
+C wasm/JS:\sdocumented\sDB.selectValue()\sand\scorrected\sthe\sfetching\sof\sNULL\scolumns\svia\sStmt.get().
+D 2022-05-24T00:35:18.252
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 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -65,10 +65,10 @@ F ext/fiddle/fiddle-worker.js e87c17070b979bd057a6849332f2a86660a4255ff7f1b6671e
 F ext/fiddle/fiddle.html 657c6c3f860c322fba3c69fa4f7a1209e2d2ce44b4bc65a3e154e3a97c047a7c
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+F ext/fiddle/sqlite3-api.js 2a0ba8c9a0778a6ea6720c6717540732a8eb36b7605b883a716db3da9d4a2aba
 F ext/fiddle/testing-common.js 723aada13d90a5ee3f0f8f5b5b88e46954becae5d2b04ded811d90106057f4ac
 F ext/fiddle/testing1.html 026502e5d5e6a250e4101f8e8948708a1295ce831a094d741839ecaf788d8533
-F ext/fiddle/testing1.js 7365c6dac4f680f8ebd6ecfcf6475c5c0a0afd61cdaff5b5281e473b79c7424e
+F ext/fiddle/testing1.js 2f9910ff46bcd31ed2779b4bd2fcf09a57805c6073da6dd56dce6cd2e95a47b9
 F ext/fts1/README.txt 20ac73b006a70bcfd80069bdaf59214b6cf1db5e
 F ext/fts1/ft_hash.c 3927bd880e65329bdc6f506555b228b28924921b
 F ext/fts1/ft_hash.h 06df7bba40dadd19597aa400a875dbc2fed705ea
@@ -1968,8 +1968,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
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-P 6044605b2a712da73600cabb967797a03ed1915dc0ab0b10edbd52525e548196
-R ceb272ebfbe3295f001f5fea9e36326e
+P 325a9ee31ad7abae563c4da5cd8228e151b00aa9afcac7e9bca5efaa9d48e107
+R ec73c1d66717375855af09a51e0d10ff
 U stephan
-Z 228a27040854e49e332f67b566615c59
+Z 005deadcf1ed546088d3a014fe907d3d
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
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+70f91fab825d365f505750acdb8d3ae532880c4cdb64d1e61bb21b24a115958b