Fossil

*/
static sqlite3_stmt * Th_GetStmt(Th_Interp *interp, int stmtId);


struct Th_Sqlite {
  sqlite3_stmt ** aStmt;
  int nStmt;
  int colCmdIndex;
};
#define Th_Sqlite_KEY "Th_Sqlite"
typedef struct Th_Sqlite Th_Sqlite;

static Th_Sqlite * Th_sqlite_manager( Th_Interp * interp ){
  void * p = Th_Data_Get( interp, Th_Sqlite_KEY );
  return p ? (Th_Sqlite*)p : NULL;

}

/*
** TH Syntax:
**
** query col string stmtId Index
** query stmtId col string Index
** query stmtId col Index string
**
** Returns the result column value at the given 0-based index.
*/
static int queryColStringCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 

}

/*
** TH Syntax:
**
** query col int stmtId Index
** query stmtId col int Index
** query stmtId col Index int
**
** Returns the result column value at the given 0-based index.
*/
static int queryColIntCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 

}

/*
** TH Syntax:
**
** query col double stmtId Index
** query stmtId col double Index
** query stmtId col Index double
**
** Returns the result column value at the given 0-based index.
*/
static int queryColDoubleCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 

  Th_SetResultDouble( interp, sqlite3_column_double( pStmt, index ) );
  return TH_OK;
}

/*
** TH Syntax:
**
** query col isnull stmtId Index
** query stmtId col is_null Index
** query stmtId col Index isnull
**
** Returns non-0 if the given 0-based result column index contains
** an SQL NULL value, else returns 0.
*/
static int queryColIsNullCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 
  const char **argv, 
  int *argl
){
  Th_Sqlite * sq = Th_sqlite_manager(interp);
  int index = sq->colCmdIndex;
  sqlite3_stmt * pStmt = (sqlite3_stmt*)p;
  int requireArgc = pStmt ? 2 : 3;
  if( index >= 0 ) --requireArgc;
  double rc = 0;

  if( argc!=requireArgc ){
    return Th_WrongNumArgs2(interp,
                            argv[0], argl[0],
                            "StmtHandle Index");
  }
  if(!pStmt){
    queryStmtIndexArgs(interp, argc, argv, argl, &pStmt, &index);
  }else if(index<0){
    Th_ToInt(interp, argv[1], argl[1], &index);
  }
  if(index < 0){
    return TH_ERROR;
  }
  Th_SetResultInt( interp,
                   SQLITE_NULL==sqlite3_column_type( pStmt, index )
                   ? 1 : 0);
  return TH_OK;
}

/*
** TH Syntax:
**
** query col type stmtId Index
** query stmtId col type Index
** query stmtId col Index type
**
** Returns the sqlite type identifier for the given 0-based result
** column index. The values are available in TH as $SQLITE_NULL,
** $SQLITE_INTEGER, etc.
*/
static int queryColTypeCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 
  const char **argv, 
  int *argl
){
  Th_Sqlite * sq = Th_sqlite_manager(interp);
  int index = sq->colCmdIndex;
  sqlite3_stmt * pStmt = (sqlite3_stmt*)p;
  int requireArgc = pStmt ? 2 : 3;
  if( index >= 0 ) --requireArgc;
  double rc = 0;

  if( argc!=requireArgc ){
    return Th_WrongNumArgs2(interp,
                            argv[0], argl[0],
                            "StmtHandle Index");
  }
  if(!pStmt){
    queryStmtIndexArgs(interp, argc, argv, argl, &pStmt, &index);
  }else if(index<0){
    Th_ToInt( interp, argv[1], argl[1], &index );
  }
  if(index < 0){
    return TH_ERROR;
  }
  Th_SetResultInt( interp, sqlite3_column_type( pStmt, index ) );
  return TH_OK;

}

/*
** TH Syntax:
**
** query col name stmtId Index
** query stmtId col name Index
** query stmtId col Index name 
**
** Returns the result column name at the given 0-based index.
*/
static int queryColNameCmd(
  Th_Interp *interp,
  void *p, 
  int argc, 
  const char **argv, 
  int *argl
){
  Th_Sqlite * sq = Th_sqlite_manager(interp);
  int index = sq->colCmdIndex;
  sqlite3_stmt * pStmt = (sqlite3_stmt*)p;
  int requireArgc = pStmt ? 2 : 3;
  char const * val;
  int rc = 0;
  if( index >= 0 ) --requireArgc;
  if( argc!=requireArgc ){
    return Th_WrongNumArgs2(interp,
                            argv[0], argl[0],
                            "StmtHandle Index");
  }
  if(!pStmt){
    queryStmtIndexArgs(interp, argc, argv, argl, &pStmt, &index);
  }else if(index<0){
    Th_ToInt( interp, argv[1], argl[1], &index );
  }
  if(index < 0){
    return TH_ERROR;
  }
  assert(NULL!=pStmt);
  val = sqlite3_column_name( pStmt, index );

}

/*
** TH Syntax:
**
** query col time stmtId Index format
** query stmtId col name Index format
** query stmtId col Index name format
**
** Returns the result column name at the given 0-based index.
*/
static int queryColTimeCmd(
  Th_Interp *interp,
  void *ctx, 
  int argc, 
  const char **argv, 
  int *argl
){
  Th_Sqlite * sq = Th_sqlite_manager(interp);
  int index = sq->colCmdIndex;
  sqlite3_stmt * pStmt = (sqlite3_stmt*)ctx;
  int minArgs = pStmt ? 3 : 4;
  int argPos;
  char const * val;
  char * fval;
  int i, rc = 0;

  char const * fmt;
  Blob sql = empty_blob;
  if( index >= 0 ) --minArgs;
  if( argc<minArgs ){
    return Th_WrongNumArgs2(interp,
                            argv[0], argl[0],
                            "StmtHandle Index Format");
  }
  if(!pStmt){
    queryStmtIndexArgs(interp, argc, argv, argl, &pStmt, &index);
    argPos = 3;
  }else if(index<0){
    Th_ToInt( interp, argv[1], argl[1], &index );
    argPos = 2;
  }else{
    argPos = 1;
  }
  if(index < 0){
    return TH_ERROR;
  }
  val = sqlite3_column_text( pStmt, index );
  fmt = argv[argPos++];
  assert(NULL!=pStmt);

static int queryColTopLevelCmd(
  Th_Interp *interp,
  void *ctx, 
  int argc, 
  const char **argv, 
  int *argl
){
  int colIndex = -1;
  static Th_SubCommand aSub[] = {
    {"count",   queryColCountCmd},
    {"is_null", queryColIsNullCmd},
    {"isnull",  queryColIsNullCmd},
    {"name",    queryColNameCmd},
    {"double",  queryColDoubleCmd},
    {"int",     queryColIntCmd},
    {"string",  queryColStringCmd},
    {"time",    queryColTimeCmd},
    {"type",    queryColTypeCmd},
    {0, 0}
  };
  static Th_SubCommand aSubWithIndex[] = {
    {"is_null", queryColIsNullCmd},
    {"isnull",  queryColIsNullCmd},
    {"name",    queryColNameCmd},
    {"double",  queryColDoubleCmd},
    {"int",     queryColIntCmd},
    {"string",  queryColStringCmd},
    {"time",    queryColTimeCmd},
    {"type",    queryColTypeCmd},
    {0, 0}
  };
  Th_Sqlite * sq = Th_sqlite_manager(interp);
  assert(NULL != sq);
  if( 1 == argc ){
      Th_WrongNumArgs2( interp, argv[0], argl[0],
                        "subcommand");
      return TH_ERROR;
  }else if( 0 == Th_TryInt(interp,argv[1], argl[1], &colIndex) ){
    if(colIndex <0){
      Th_ErrorMessage( interp, "Invalid column index.", NULL, 0);
      return TH_ERROR;
    }
    ++argv;
    ++argl;
    --argc;
  }
  sq->colCmdIndex = colIndex;
  /* TODO: accept the index as the first param after "col", and make
     subcommands aware of sq->colCmdIndex.
  */
  Th_CallSubCommand2( interp, ctx, argc, argv, argl,
                      (colIndex<0) ? aSub : aSubWithIndex );
}


static int queryTopLevelCmd(
  Th_Interp *interp,
  void *ctx, 
  int argc, 

The <tt>bind xxx</tt> family of subcommands attach values to queries
before stepping through them. The subcommands include:

   *  <tt>bind int StmtId Index Value</tt>
   *  <tt>bind double StmtId Index Value</tt>
   *  <tt>bind null StmtId Index</tt>
   *  <tt>bind string StmtId Index Value</tt>

Note that all of those optionally accept the statement handle directly after
the "query" command (before the "col" subcommand). e.g.
<tt>query bind null $stmt 1</tt> and
<tt>query $stmt bind null 1</tt> are equivalent.


Achtung: the bind API uses 1-based indexes, just like SQL does.

<nowiki><pre>
set stmt [query prepare "SELECT ... WHERE user=?"]
query $stmt bind int 1 drh
if {0 &lt; [query $stmt step]} {
   puts [query $stmt col string 0] "\n"
}
query $stmt finalize
</pre></nowiki>


<h2>col xxx</h2>

The <tt>col xxx</tt> familys of subcommands are for fetching
values and metadata from result rows.

   *  <tt>col count StmtId</tt> Returns the number of result columns in the statement.
   *  <tt>col isnull StmtId Index</tt> Returns non-0 if the given column contains an SQL NULL value.
   *  <tt>col double StmtId Index</tt>
   *  <tt>col int StmtId Index</tt>
   *  <tt>col string StmtId Index</tt>
   *  <tt>col string StmtId Index Format Modifiers</tt> See below.
   *  <tt>col type StmtId Index</tt> Return value corresponds to one of the <tt>SQLITE_TYPENAME</tt> family of constants.

Note that all of those optionally accept the statement handle directly after
the "query" command (before the "col" subcommand). e.g.
<tt>query $stmt col count</tt> and
<tt>query col count $stmt</tt> are equivalent. They also accept the column index
either before or after the type name, e.g.
<tt>query $stmt col 1 string</tt> and <tt>query $stmt col string 1</tt> are equivalent.

Achtung: the col API uses 0-based indexes, just like SQL does.

<h3>col time</h3>

This function is a proxy for sqlite3's
<tt>[http://www.sqlite.org/lang_datefunc.html|strftime()]</tt> function. It is used like this: