pike.git/ lib/ modules/ Sql.pmod/ sql_util.pmod > 51f823c856c5b4525cb82960274b471529f9027a [Annotate]

/* 

 * $Id: sql_util.pmod,v 1.22 2008/06/28 16:49:55 nilsson Exp $ 

 * 

 * Some SQL utility functions. 

 * They are kept here to avoid circular references. 

 * 

 * Henrik Grubbström 1999-07-01 

 */ 

#pike __REAL_VERSION__ 

//! Some SQL utility functions 

//! Quote a string so that it can safely be put in a query. 

//! 

//! @param s 

//!   String to quote. 

string quote(string s) 

{ 

  return replace(s, "\'", "\'\'"); 

} 

//! Throw an error in case an unimplemented function is called. 

void fallback() 

{ 

  error( "Function not supported in this database." ); 

} 

//! Build a raw SQL query, given the cooked query and the variable bindings 

//! It's meant to be used as an emulation engine for those drivers not 

//! providing such a behaviour directly (i.e. Oracle). 

//! The raw query can contain some variables (identified by prefixing 

//! a colon to a name or a number (i.e. ":var" or  ":2"). They will be 

//! replaced by the corresponding value in the mapping. 

//! 

//! @param query 

//!   The query. 

//! 

//! @param bindings 

//!   Optional mapping containing the variable bindings. Make sure that 

//!   no confusion is possible in the query. If necessary, change the 

//!   variables' names. 

string emulate_bindings(string query, mapping(string|int:mixed)|void bindings, 

                        void|object driver) 

{ 

  array(string)k, v; 

  if (!bindings) 

    return query; 

  function my_quote=(driver&&driver->quote?driver->quote:quote); 

  v=map(values(bindings), 

        lambda(mixed m) { 

          if(multisetp(m)) m = indices(m)[0]; 

          return (stringp(m)? "'"+my_quote(m)+"'" : 

           zero_type(m)?"NULL":(string)m); 

        }); 

  // Throws if mapping key is empty string. 

  k=map(indices(bindings),lambda(string s){ 

                            return ( (stringp(s)&&s[0]==':') ? 

                                     s : ":"+s); 

                          }); 

  return replace(query,k,v); 

} 

//! Result object wrapper performing utf8 decoding of all fields. 

class UnicodeWrapper ( 

                      // The wrapped result object. 

                      protected object master_result 

                      ) 

{ 

  //! Returns the number of rows in the result. 

  int num_rows() 

  { 

    return master_result->num_rows(); 

  } 

  //! Returns the number of fields in the result. 

  int num_fields() 

  { 

    return master_result->num_fields(); 

  } 

  //! Returns @expr{1@} if there are no more rows in the result. 

  int(0..1) eof() 

  { 

    return master_result->eof(); 

  } 

  //! Cached @[fetch_fields()] result. 

  protected array(int|mapping(string:mixed)) field_info; 

  //! Returns Information about the fields in the result. 

  //! 

  //! The following fields are converted from UTF8 if present: 

  //! @mapping 

  //!   @member string "name" 

  //!     The name of the field. Always present. 

  //!   @member string "table" 

  //!     The table the field is from. Not present from all databases. 

  //!   @member string "default" 

  //!     The default value for the column. Not available from all databases. 

  //! @endmapping 

  array(int|mapping(string:mixed)) fetch_fields() 

  { 

    if (!field_info) { 

      field_info = master_result->fetch_fields(); 

      foreach(field_info, int|mapping(string:mixed) field) { 

        if (mappingp(field)) { 

          field->name = utf8_to_string(field->name); 

          if (field->table) { 

            field->table = utf8_to_string(field->table); 

          } 

          if (field->default) { 

            field->default = utf8_to_string(field->default); 

          } 

        } 

      } 

    } 

    return field_info; 

  } 

  //! Skip ahead the specified number of rows. 

  void seek(int rows) 

  { 

    master_result->seek(rows); 

  } 

  //! Fetch the next row from the result. 

  //! 

  //! All strings in the result are decoded from UTF8. 

  int|array(string) fetch_row() 

  { 

    int|array(string) row = master_result->fetch_row(); 

    if (!arrayp(row)) return row; 

    array(int|mapping(string:mixed)) field_info = fetch_fields(); 

    foreach(row; int i; string|int val) { 

      if (stringp(val)) { 

        row[i] = utf8_to_string(val); 

      } 

    } 

    return row; 

  } 

} 

#if constant (Mysql.mysql.HAVE_MYSQL_FIELD_CHARSETNR) 

class MySQLUnicodeWrapper 

//! Result wrapper for MySQL that performs UTF-8 decoding of all 

//! nonbinary fields. Useful if the result charset of the connection 

//! has been set to UTF-8. 

//! 

//! @note 

//! There's normally no need to use this class directly. It's used 

//! automatically when @[Mysql.set_unicode_decode_mode] is activated. 

{ 

  inherit UnicodeWrapper; 

  int|array(string) fetch_row() 

  { 

    int|array(string) row = master_result->fetch_row(); 

    if (!arrayp(row)) return row; 

    array(int|mapping(string:mixed)) field_info = fetch_fields(); 

    foreach(row; int i; string|int val) { 

      if (stringp(val) && field_info[i]->charsetnr != 63) { 

        row[i] = utf8_to_string(val); 

      } 

    } 

    return row; 

  } 

} 

#else 

class MySQLBrokenUnicodeWrapper 

// This one is used to get a buggy unicode support when compiled with 

// an old MySQL client lib that doesn't have the charsetnr property in 

// the field info. It looks at the binary flag instead, which is set 

// for binary fields but might also be set for text fields (e.g. with 

// a definition like "VARCHAR(255) BINARY"). 

// 

// I.e. the effect of using this one is that text fields with the 

// binary flag won't be correctly decoded in unicode decode mode. 

// 

// This has to be enabled either by passing "broken-unicode" as 

// charset to Sql.mysql.create or Sql.mysql.set_charset, by calling 

// Sql.mysql.set_unicode_decode_mode(-1), or by defining the 

// environment variable PIKE_BROKEN_MYSQL_UNICODE_MODE. That will 

// cause this buggy variant to be used if and only if the MySQL client 

// lib doesn't support the charsetnr property. 

{ 

  inherit UnicodeWrapper; 

  int|array(string) fetch_row() 

  { 

    int|array(string) row = master_result->fetch_row(); 

    if (!arrayp(row)) return row; 

    array(int|mapping(string:mixed)) field_info = fetch_fields(); 

    foreach(row; int i; string|int val) { 

      if (stringp(val) && field_info[i]->flags && 

          !field_info[i]->flags->binary) { 

        row[i] = utf8_to_string(val); 

      } 

    } 

    return row; 

  } 

} 

#endif