Add the new "bind_fallback" method to the "sqlite3" object in the TCL

interface.

FossilOrigin-Name: c7f70b6d96338dba201e005104e7f7148c1a8cd767ab05e35b44617c4c797bc5

1 files changed, 99 insertions, 28 deletions

diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index 1b0086c7d..a78d5676c 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -159,6 +159,7 @@ struct SqliteDb {
   char *zTraceV2;            /* The trace_v2 callback routine */
   char *zProfile;            /* The profile callback routine */
   char *zProgress;           /* The progress callback routine */
+  char *zBindFallback;       /* Callback to invoke on a binding miss */
   char *zAuth;               /* The authorization callback routine */
   int disableAuth;           /* Disable the authorizer if it exists */
   char *zNull;               /* Text to substitute for an SQL NULL value */
@@ -549,6 +550,9 @@ static void SQLITE_TCLAPI DbDeleteCmd(void *db){
   if( pDb->zProfile ){
     Tcl_Free(pDb->zProfile);
   }
+  if( pDb->zBindFallback ){
+    Tcl_Free(pDb->zBindFallback);
+  }
   if( pDb->zAuth ){
     Tcl_Free(pDb->zAuth);
   }
@@ -1301,6 +1305,8 @@ static int dbPrepareAndBind(
   int iParm = 0;                  /* Next free entry in apParm */
   char c;
   int i;
+  int needResultReset = 0;        /* Need to invoke Tcl_ResetResult() */
+  int rc = SQLITE_OK;             /* Value to return */
   Tcl_Interp *interp = pDb->interp;
 
   *ppPreStmt = 0;
@@ -1388,6 +1394,25 @@ static int dbPrepareAndBind(
     const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
     if( zVar!=0 && (zVar[0]=='$' || zVar[0]==':' || zVar[0]=='@') ){
       Tcl_Obj *pVar = Tcl_GetVar2Ex(interp, &zVar[1], 0, 0);
+      if( pVar==0 && pDb->zBindFallback!=0 ){
+        Tcl_Obj *pCmd;
+        int rx;
+        pCmd = Tcl_NewStringObj(pDb->zBindFallback, -1);
+        Tcl_IncrRefCount(pCmd);
+        Tcl_ListObjAppendElement(interp, pCmd, Tcl_NewStringObj(zVar,-1));
+        if( needResultReset ) Tcl_ResetResult(interp);
+        needResultReset = 1;
+        rx = Tcl_EvalObjEx(interp, pCmd, TCL_EVAL_DIRECT);
+        Tcl_DecrRefCount(pCmd);
+        if( rx==TCL_OK ){
+          pVar = Tcl_GetObjResult(interp);
+        }else if( rx==TCL_ERROR ){
+          rc = TCL_ERROR;
+          break;
+        }else{
+          pVar = 0;
+        }
+      }
       if( pVar ){
         int n;
         u8 *data;
@@ -1423,12 +1448,14 @@ static int dbPrepareAndBind(
       }else{
         sqlite3_bind_null(pStmt, i);
       }
+      if( needResultReset ) Tcl_ResetResult(pDb->interp);
     }
   }
   pPreStmt->nParm = iParm;
   *ppPreStmt = pPreStmt;
+  if( needResultReset && rc==TCL_OK ) Tcl_ResetResult(pDb->interp);
 
-  return TCL_OK;
+  return rc;
 }
 
 /*
@@ -1887,35 +1914,36 @@ static int SQLITE_TCLAPI DbObjCmd(
   int choice;
   int rc = TCL_OK;
   static const char *DB_strs[] = {
-    "authorizer",             "backup",                "busy",
-    "cache",                  "changes",               "close",
-    "collate",                "collation_needed",      "commit_hook",
-    "complete",               "copy",                  "deserialize",
-    "enable_load_extension",  "errorcode",             "eval",
-    "exists",                 "function",              "incrblob",
-    "interrupt",              "last_insert_rowid",     "nullvalue",
-    "onecolumn",              "preupdate",             "profile",
-    "progress",               "rekey",                 "restore",
-    "rollback_hook",          "serialize",             "status",
-    "timeout",                "total_changes",         "trace",
-    "trace_v2",               "transaction",           "unlock_notify",
-    "update_hook",            "version",               "wal_hook",
-    0                        
+    "authorizer",             "backup",                "bind_fallback",
+    "busy",                   "cache",                 "changes",
+    "close",                  "collate",               "collation_needed",
+    "commit_hook",            "complete",              "copy",
+    "deserialize",            "enable_load_extension", "errorcode",
+    "eval",                   "exists",                "function",
+    "incrblob",               "interrupt",             "last_insert_rowid",
+    "nullvalue",              "onecolumn",             "preupdate",
+    "profile",                "progress",              "rekey",
+    "restore",                "rollback_hook",         "serialize",
+    "status",                 "timeout",               "total_changes",
+    "trace",                  "trace_v2",              "transaction",
+    "unlock_notify",          "update_hook",           "version",
+    "wal_hook",               0                        
   };
   enum DB_enum {
-    DB_AUTHORIZER,            DB_BACKUP,               DB_BUSY,
-    DB_CACHE,                 DB_CHANGES,              DB_CLOSE,
-    DB_COLLATE,               DB_COLLATION_NEEDED,     DB_COMMIT_HOOK,
-    DB_COMPLETE,              DB_COPY,                 DB_DESERIALIZE,
-    DB_ENABLE_LOAD_EXTENSION, DB_ERRORCODE,            DB_EVAL,
-    DB_EXISTS,                DB_FUNCTION,             DB_INCRBLOB,
-    DB_INTERRUPT,             DB_LAST_INSERT_ROWID,    DB_NULLVALUE,
-    DB_ONECOLUMN,             DB_PREUPDATE,            DB_PROFILE,
-    DB_PROGRESS,              DB_REKEY,                DB_RESTORE,
-    DB_ROLLBACK_HOOK,         DB_SERIALIZE,            DB_STATUS,
-    DB_TIMEOUT,               DB_TOTAL_CHANGES,        DB_TRACE,
-    DB_TRACE_V2,              DB_TRANSACTION,          DB_UNLOCK_NOTIFY,
-    DB_UPDATE_HOOK,           DB_VERSION,              DB_WAL_HOOK
+    DB_AUTHORIZER,            DB_BACKUP,               DB_BIND_FALLBACK,
+    DB_BUSY,                  DB_CACHE,                DB_CHANGES,
+    DB_CLOSE,                 DB_COLLATE,              DB_COLLATION_NEEDED,
+    DB_COMMIT_HOOK,           DB_COMPLETE,             DB_COPY,
+    DB_DESERIALIZE,           DB_ENABLE_LOAD_EXTENSION,DB_ERRORCODE,
+    DB_EVAL,                  DB_EXISTS,               DB_FUNCTION,
+    DB_INCRBLOB,              DB_INTERRUPT,            DB_LAST_INSERT_ROWID,
+    DB_NULLVALUE,             DB_ONECOLUMN,            DB_PREUPDATE,
+    DB_PROFILE,               DB_PROGRESS,             DB_REKEY,
+    DB_RESTORE,               DB_ROLLBACK_HOOK,        DB_SERIALIZE,
+    DB_STATUS,                DB_TIMEOUT,              DB_TOTAL_CHANGES,
+    DB_TRACE,                 DB_TRACE_V2,             DB_TRANSACTION,
+    DB_UNLOCK_NOTIFY,         DB_UPDATE_HOOK,          DB_VERSION,
+    DB_WAL_HOOK             
   };
   /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */
 
@@ -2037,6 +2065,49 @@ static int SQLITE_TCLAPI DbObjCmd(
     break;
   }
 
+  /*    $db bind_fallback ?CALLBACK?
+  **
+  ** When resolving bind parameters in an SQL statement, if the parameter
+  ** cannot be associated with a TCL variable then invoke CALLBACK with a
+  ** single argument that is the name of the parameter and use the return
+  ** value of the CALLBACK as the binding.  If CALLBACK returns something
+  ** other than TCL_OK or TCL_ERROR then bind a NULL.
+  **
+  ** If CALLBACK is an empty string, then revert to the default behavior 
+  ** which is to set the binding to NULL.
+  **
+  ** If CALLBACK returns an error, that causes the statement execution to
+  ** abort.  Hence, to configure a connection so that it throws an error
+  ** on an attempt to bind an unknown variable, do something like this:
+  **
+  **     proc bind_error {name} {error "no such variable: $name"}
+  **     db bind_fallback bind_error
+  */
+  case DB_BIND_FALLBACK: {
+    if( objc>3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
+      return TCL_ERROR;
+    }else if( objc==2 ){
+      if( pDb->zBindFallback ){
+        Tcl_AppendResult(interp, pDb->zBindFallback, (char*)0);
+      }
+    }else{
+      char *zCallback;
+      int len;
+      if( pDb->zBindFallback ){
+        Tcl_Free(pDb->zBindFallback);
+      }
+      zCallback = Tcl_GetStringFromObj(objv[2], &len);
+      if( zCallback && len>0 ){
+        pDb->zBindFallback = Tcl_Alloc( len + 1 );
+        memcpy(pDb->zBindFallback, zCallback, len+1);
+      }else{
+        pDb->zBindFallback = 0;
+      }
+    }
+    break;
+  }
+
   /*    $db busy ?CALLBACK?
   **
   ** Invoke the given callback if an SQL statement attempts to open