class SQLite3::Database - sqlite3-1.3.10 Documentation

# class SQLite3::Database

The Database class encapsulates a single connection to a SQLite3 database. Its usage is very straightforward:

    require 'sqlite3'

    SQLite3::Database.new( "data.db" ) do |db|
      db.execute( "select * from table" ) do |row|
        p row
      end
    end

It wraps the lower-level methods provides by the selected driver, and includes the Pragmas module for access to various pragma convenience methods.

The Database class provides type translation services as well, by which the SQLite3 data types (which are all represented as strings) may be converted into their corresponding types (as defined in the schemas for their tables). This translation only occurs when querying data from the database–insertions and updates are all still typeless.

Furthermore, the Database class has been designed to work well with the ArrayFields module from Ara Howard. If you require the ArrayFields module before performing a query, and if you have not enabled results as hashes, then the results will all be indexible by field name.

### Attributes

collations[R]
results_as_hash[RW]

A boolean that indicates whether rows in result sets should be returned as hashes or not. By default, rows are returned as arrays.

### Public Class Methods

finalize( &block ) click to toggle source

    # File lib/sqlite3/database.rb, line 374
    def self.finalize( &block )
      define_method(:finalize, &block)
    end

SQLite3::Database.new(file, options = {}) click to toggle source

Create a new Database object that opens the given file. If utf16 is `true`, the filename is interpreted as a UTF-16 encoded string.

By default, the new database will return result rows as arrays (#results_as_hash) and has type translation disabled (#type_translation=).

    static VALUE initialize(int argc, VALUE *argv, VALUE self)
    {
      sqlite3RubyPtr ctx;
      VALUE file;
      VALUE opts;
      VALUE zvfs;
    #ifdef HAVE_SQLITE3_OPEN_V2
      int mode = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
    #endif
      int status;

      Data_Get_Struct(self, sqlite3Ruby, ctx);

      rb_scan_args(argc, argv, "12", &file, &opts, &zvfs);
    #if defined StringValueCStr
      StringValuePtr(file);
      rb_check_safe_obj(file);
    #else
      Check_SafeStr(file);
    #endif
      if(NIL_P(opts)) opts = rb_hash_new();
      else Check_Type(opts, T_HASH);

    #ifdef HAVE_RUBY_ENCODING_H
      if(UTF16_LE_P(file) || UTF16_BE_P(file)) {
        status = sqlite3_open16(utf16_string_value_ptr(file), &ctx->db);
      } else {
    #endif

        if(Qtrue == rb_hash_aref(opts, sym_utf16)) {
          status = sqlite3_open16(utf16_string_value_ptr(file), &ctx->db);
        } else {

    #ifdef HAVE_RUBY_ENCODING_H
          if(!UTF8_P(file)) {
            file = rb_str_export_to_enc(file, rb_utf8_encoding());
          }
    #endif

          if (Qtrue == rb_hash_aref(opts, ID2SYM(rb_intern("readonly")))) {
    #ifdef HAVE_SQLITE3_OPEN_V2
            mode = SQLITE_OPEN_READONLY;
    #else
            rb_raise(rb_eNotImpError, "sqlite3-ruby was compiled against a version of sqlite that does not support readonly databases");
    #endif
          }
    #ifdef HAVE_SQLITE3_OPEN_V2
          status = sqlite3_open_v2(
              StringValuePtr(file),
              &ctx->db,
              mode,
              NIL_P(zvfs) ? NULL : StringValuePtr(zvfs)
          );
    #else
          status = sqlite3_open(
              StringValuePtr(file),
              &ctx->db
          );
    #endif
        }

    #ifdef HAVE_RUBY_ENCODING_H
      }
    #endif

      CHECK(ctx->db, status)

      rb_iv_set(self, "@tracefunc", Qnil);
      rb_iv_set(self, "@authorizer", Qnil);
      rb_iv_set(self, "@encoding", Qnil);
      rb_iv_set(self, "@busy_handler", Qnil);
      rb_iv_set(self, "@collations", rb_hash_new());
      rb_iv_set(self, "@functions", rb_hash_new());
      rb_iv_set(self, "@results_as_hash", rb_hash_aref(opts, sym_results_as_hash));
      rb_iv_set(self, "@type_translation", rb_hash_aref(opts, sym_type_translation));
    #ifdef HAVE_SQLITE3_OPEN_V2
      rb_iv_set(self, "@readonly", mode == SQLITE_OPEN_READONLY ? Qtrue : Qfalse);
    #else
      rb_iv_set(self, "@readonly", Qfalse);
    #endif

      if(rb_block_given_p()) {
        rb_yield(self);
        rb_funcall(self, rb_intern("close"), 0);
      }

      return self;
    }

Also aliased as: open
open(p1, p2 = v2, p3 = v3)
Alias for: new
quote( string ) click to toggle source

Quotes the given string, making it safe to use in an SQL statement. It replaces all instances of the single-quote character with two single-quote characters. The modified string is returned.

    # File lib/sqlite3/database.rb, line 47
    def quote( string )
      string.gsub( /'/, "''" )
    end

step( &block ) click to toggle source

    # File lib/sqlite3/database.rb, line 370
    def self.step( &block )
      define_method(:step, &block)
    end

### Public Instance Methods

authorizer( &block ) click to toggle source

Installs (or removes) a block that will be invoked for every access to the database. If the block returns 0 (or `nil`), the statement is allowed to proceed. Returning 1 causes an authorization error to occur, and returning 2 causes the access to be silently denied.

    # File lib/sqlite3/database.rb, line 81
    def authorizer( &block )
      self.authorizer = block
    end

set_authorizer = auth click to toggle source

Set the authorizer for this database. `auth` must respond to `call`, and `call` must take 5 arguments.

Installs (or removes) a block that will be invoked for every access to the database. If the block returns 0 (or `true`), the statement is allowed to proceed. Returning 1 or false causes an authorization error to occur, and returning 2 or nil causes the access to be silently denied.

    static VALUE set_authorizer(VALUE self, VALUE authorizer)
    {
      sqlite3RubyPtr ctx;
      int status;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      status = sqlite3_set_authorizer(
          ctx->db, NIL_P(authorizer) ? NULL : rb_sqlite3_auth, (void *)self
      );

      CHECK(ctx->db, status);

      rb_iv_set(self, "@authorizer", authorizer);

      return self;
    }

busy_handler { |count| ... } click to toggle source
busy_handler(Class.new { def call count; end }.new)

Register a busy handler with this database instance. When a requested resource is busy, this handler will be invoked. If the handler returns `false`, the operation will be aborted; otherwise, the resource will be requested again.

The handler will be invoked with the name of the resource that was busy, and the number of times it has been retried.

See also the mutually exclusive busy_timeout.

    static VALUE busy_handler(int argc, VALUE *argv, VALUE self)
    {
      sqlite3RubyPtr ctx;
      VALUE block;
      int status;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      rb_scan_args(argc, argv, "01", &block);

      if(NIL_P(block) && rb_block_given_p()) block = rb_block_proc();

      rb_iv_set(self, "@busy_handler", block);

      status = sqlite3_busy_handler(
          ctx->db, NIL_P(block) ? NULL : rb_sqlite3_busy_handler, (void *)self);

      CHECK(ctx->db, status);

      return self;
    }

busy_timeout(p1)
Alias for: busy_timeout=
busy_timeout = ms click to toggle source

Indicates that if a request for a resource terminates because that resource is busy, SQLite should sleep and retry for up to the indicated number of milliseconds. By default, SQLite does not retry busy resources. To restore the default behavior, send 0 as the `ms` parameter.

See also the mutually exclusive busy_handler.

    static VALUE set_busy_timeout(VALUE self, VALUE timeout)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      CHECK(ctx->db, sqlite3_busy_timeout(ctx->db, (int)NUM2INT(timeout)));

      return self;
    }

Also aliased as: busy_timeout
changes click to toggle source

Returns the number of changes made to this database instance by the last operation performed. Note that a “delete from table” without a where clause will not affect this value.

    static VALUE changes(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return INT2NUM(sqlite3_changes(ctx->db));
    }

close click to toggle source

Closes this database.

    static VALUE sqlite3_rb_close(VALUE self)
    {
      sqlite3RubyPtr ctx;
      sqlite3 * db;
      Data_Get_Struct(self, sqlite3Ruby, ctx);

      db = ctx->db;
      CHECK(db, sqlite3_close(ctx->db));

      ctx->db = NULL;

      return self;
    }

closed? click to toggle source

Returns `true` if this database instance has been closed (see close).

    static VALUE closed_p(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);

      if(!ctx->db) return Qtrue;

      return Qfalse;
    }

collation(name, comparator) click to toggle source

Add a collation with name `name`, and a `comparator` object. The `comparator` object should implement a method called “compare” that takes two parameters and returns an integer less than, equal to, or greater than 0.

    static VALUE collation(VALUE self, VALUE name, VALUE comparator)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      CHECK(ctx->db, sqlite3_create_collation(
            ctx->db,
            StringValuePtr(name),
            SQLITE_UTF8,
            (void *)comparator,
            NIL_P(comparator) ? NULL : rb_comparator_func));

      /* Make sure our comparator doesn't get garbage collected. */
      rb_hash_aset(rb_iv_get(self, "@collations"), name, comparator);

      return self;
    }

complete?(sql) click to toggle source

Return `true` if the string is a valid (ie, parsable) SQL statement, and `false` otherwise.

    static VALUE complete_p(VALUE UNUSED(self), VALUE sql)
    {
      if(sqlite3_complete(StringValuePtr(sql)))
        return Qtrue;

      return Qfalse;
    }

create_aggregate( name, arity, step=nil, finalize=nil, text_rep=Constants::TextRep::ANY, &block ) click to toggle source

Creates a new aggregate function for use in SQL statements. Aggregate functions are functions that apply over every row in the result set, instead of over just a single row. (A very common aggregate function is the “count” function, for determining the number of rows that match a query.)

The new function will be added as `name`, with the given `arity`. (For variable arity functions, use -1 for the arity.)

The `step` parameter must be a proc object that accepts as its first parameter a FunctionProxy instance (representing the function invocation), with any subsequent parameters (up to the function's arity). The `step` callback will be invoked once for each row of the result set.

The `finalize` parameter must be a `proc` object that accepts only a single parameter, the FunctionProxy instance representing the current function invocation. It should invoke SQLite3::FunctionProxy#result to store the result of the function.

Example:

    db.create_aggregate( "lengths", 1 ) do
      step do |func, value|
        func[ :total ] ||= 0
        func[ :total ] += ( value ? value.length : 0 )
      end

      finalize do |func|
        func.result = func[ :total ] || 0
      end
    end

    puts db.get_first_value( "select lengths(name) from table" )

See also create_aggregate_handler for a more object-oriented approach to aggregate functions.

Calls superclass method

    # File lib/sqlite3/database.rb, line 366
    def create_aggregate( name, arity, step=nil, finalize=nil,
      text_rep=Constants::TextRep::ANY, &block )

      factory = Class.new do
        def self.step( &block )
          define_method(:step, &block)
        end

        def self.finalize( &block )
          define_method(:finalize, &block)
        end
      end

      if block_given?
        factory.instance_eval(&block)
      else
        factory.class_eval do
          define_method(:step, step)
          define_method(:finalize, finalize)
        end
      end

      proxy = factory.new
      proxy.extend(Module.new {
        attr_accessor :ctx

        def step( *args )
          super(@ctx, *args)
        end

create_function(name, arity, text_rep=Constants::TextRep::ANY, &block) click to toggle source

Creates a new function for use in SQL statements. It will be added as `name`, with the given `arity`. (For variable arity functions, use -1 for the arity.)

The block should accept at least one parameter–the FunctionProxy instance that wraps this function invocation–and any other arguments it needs (up to its arity).

The block does not return a value directly. Instead, it will invoke the SQLite3::FunctionProxy#result method on the `func` parameter and indicate the return value that way.

Example:

    db.create_function( "maim", 1 ) do |func, value|
      if value.nil?
        func.result = nil
      else
        func.result = value.split(//).sort.join
      end
    end

    puts db.get_first_value( "select maim(name) from table" )

    # File lib/sqlite3/database.rb, line 321
    def create_function name, arity, text_rep=Constants::TextRep::ANY, &block
      define_function(name) do |*args|
        fp = FunctionProxy.new
        block.call(fp, *args)
        fp.result
      end
      self
    end

define_aggregator(name, aggregator) click to toggle source

Define an aggregate function named `name` using the object `aggregator`. `aggregator` must respond to `step` and `finalize`. `step` will be called with row information and `finalize` must return the return value for the aggregator function.

    static VALUE define_aggregator(VALUE self, VALUE name, VALUE aggregator)
    {
      sqlite3RubyPtr ctx;
      int arity, status;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      arity = sqlite3_obj_method_arity(aggregator, rb_intern("step"));

      status = sqlite3_create_function(
        ctx->db,
        StringValuePtr(name),
        arity,
        SQLITE_UTF8,
        (void *)aggregator,
        NULL,
        rb_sqlite3_step,
        rb_sqlite3_final
      );

      rb_iv_set(self, "@agregator", aggregator);

      CHECK(ctx->db, status);

      return self;
    }

define_function(name) { |args,...| } click to toggle source

Define a function named `name` with `args`. The arity of the block will be used as the arity for the function defined.

    static VALUE define_function(VALUE self, VALUE name)
    {
      sqlite3RubyPtr ctx;
      VALUE block;
      int status;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      block = rb_block_proc();

      status = sqlite3_create_function(
        ctx->db,
        StringValuePtr(name),
        rb_proc_arity(block),
        SQLITE_UTF8,
        (void *)block,
        rb_sqlite3_func,
        NULL,
        NULL
      );

      CHECK(ctx->db, status);

      rb_hash_aset(rb_iv_get(self, "@functions"), name, block);

      return self;
    }

enable_load_extension(onoff) click to toggle source

Enable or disable extension loading.

    static VALUE enable_load_extension(VALUE self, VALUE onoff)
    {
      sqlite3RubyPtr ctx;
      int onoffparam;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      if (Qtrue == onoff) {
        onoffparam = 1;
      } else if (Qfalse == onoff) {
        onoffparam = 0;
      } else {
        onoffparam = (int)NUM2INT(onoff);
      }

      CHECK(ctx->db, sqlite3_enable_load_extension(ctx->db, onoffparam));

      return self;
    }

encoding click to toggle source

Fetch the encoding set on this database

    static VALUE db_encoding(VALUE self)
    {
      sqlite3RubyPtr ctx;
      VALUE enc;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      enc = rb_iv_get(self, "@encoding");

      if(NIL_P(enc)) {
        sqlite3_exec(ctx->db, "PRAGMA encoding", enc_cb, (void *)self, NULL);
      }

      return rb_iv_get(self, "@encoding");
    }

errcode click to toggle source

Return an integer representing the last error to have occurred with this database.

    static VALUE errcode_(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return INT2NUM((long)sqlite3_errcode(ctx->db));
    }

errmsg click to toggle source

Return a string describing the last error to have occurred with this database.

    static VALUE errmsg(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return rb_str_new2(sqlite3_errmsg(ctx->db));
    }

execute(sql, bind_vars = [], *args) { |type_translation ? row : ordered_map_for(columns, row)| ... } click to toggle source

Executes the given SQL statement. If additional parameters are given, they are treated as bind variables, and are bound to the placeholders in the query.

Note that if any of the values passed to this are hashes, then the key/value pairs are each bound separately, with the key being used as the name of the placeholder to bind the value to.

The block is optional. If given, it will be invoked for each row returned by the query. Otherwise, any results are accumulated into an array and returned wholesale.

See also execute2, query, and execute_batch for additional ways of executing statements.

    # File lib/sqlite3/database.rb, line 115
        def execute sql, bind_vars = [], *args, &block
          # FIXME: This is a terrible hack and should be removed but is required
          # for older versions of rails
          hack = Object.const_defined?(:ActiveRecord) && sql =~ /^PRAGMA index_list/

          if bind_vars.nil? || !args.empty?
            if args.empty?
              bind_vars = []
            else
              bind_vars = [bind_vars] + args
            end

            warn("#{caller[0]} is calling SQLite3::Database#execute with nil or multiple bind params
    without using an array.  Please switch to passing bind parameters as an array.
    Support for bind parameters as *args will be removed in 2.0.0.
    ") if $VERBOSE
          end

          prepare( sql ) do |stmt|
            stmt.bind_params(bind_vars)
            columns = stmt.columns
            stmt    = ResultSet.new(self, stmt).to_a if type_translation

            if block_given?
              stmt.each do |row|
                if @results_as_hash
                  yield type_translation ? row : ordered_map_for(columns, row)
                else
                  yield row
                end
              end
            else
              if @results_as_hash
                stmt.map { |row|
                  h = type_translation ? row : ordered_map_for(columns, row)

                  # FIXME UGH TERRIBLE HACK!
                  h['unique'] = h['unique'].to_s if hack

                  h
                }
              else
                stmt.to_a
              end
            end
          end
        end

execute2( sql, *bind_vars ) { |columns| ... } click to toggle source

Executes the given SQL statement, exactly as with execute. However, the first row returned (either via the block, or in the returned array) is always the names of the columns. Subsequent rows correspond to the data from the result set.

Thus, even if the query itself returns no rows, this method will always return at least one row–the names of the columns.

See also execute, query, and execute_batch for additional ways of executing statements.

    # File lib/sqlite3/database.rb, line 174
    def execute2( sql, *bind_vars )
      prepare( sql ) do |stmt|
        result = stmt.execute( *bind_vars )
        if block_given?
          yield stmt.columns
          result.each { |row| yield row }
        else
          return result.inject( [ stmt.columns ] ) { |arr,row|
            arr << row; arr }
        end
      end
    end

execute_batch( sql, bind_vars = [], *args ) click to toggle source

Executes all SQL statements in the given string. By contrast, the other means of executing queries will only execute the first statement in the string, ignoring all subsequent statements. This will execute each one in turn. The same bind parameters, if given, will be applied to each statement.

This always returns `nil`, making it unsuitable for queries that return rows.

    # File lib/sqlite3/database.rb, line 195
        def execute_batch( sql, bind_vars = [], *args )
          # FIXME: remove this stuff later
          unless [Array, Hash].include?(bind_vars.class)
            bind_vars = [bind_vars]
            warn("#{caller[0]} is calling SQLite3::Database#execute_batch with bind parameters
    that are not a list of a hash.  Please switch to passing bind parameters as an
    array or hash. Support for this behavior will be removed in version 2.0.0.
    ") if $VERBOSE
          end

          # FIXME: remove this stuff later
          if bind_vars.nil? || !args.empty?
            if args.empty?
              bind_vars = []
            else
              bind_vars = [nil] + args
            end

            warn("#{caller[0]} is calling SQLite3::Database#execute_batch with nil or multiple bind params
    without using an array.  Please switch to passing bind parameters as an array.
    Support for this behavior will be removed in version 2.0.0.
    ") if $VERBOSE
          end

          sql = sql.strip
          until sql.empty? do
            prepare( sql ) do |stmt|
              unless stmt.closed?
                # FIXME: this should probably use sqlite3's api for batch execution
                # This implementation requires stepping over the results.
                if bind_vars.length == stmt.bind_parameter_count
                  stmt.bind_params(bind_vars)
                end
                stmt.step
              end
              sql = stmt.remainder.strip
            end
          end
          # FIXME: we should not return `nil` as a success return value
          nil
        end

finalize() click to toggle source
Calls superclass method

    # File lib/sqlite3/database.rb, line 396
    def finalize
      super(@ctx)
    end

get_first_row( sql, *bind_vars ) click to toggle source

A convenience method for obtaining the first row of a result set, and discarding all others. It is otherwise identical to execute.

See also get_first_value.

    # File lib/sqlite3/database.rb, line 282
    def get_first_row( sql, *bind_vars )
      execute( sql, *bind_vars ).first
    end

get_first_value( sql, *bind_vars ) click to toggle source

A convenience method for obtaining the first value of the first row of a result set, and discarding all other values and rows. It is otherwise identical to execute.

See also get_first_row.

    # File lib/sqlite3/database.rb, line 291
    def get_first_value( sql, *bind_vars )
      execute( sql, *bind_vars ) { |row| return row[0] }
      nil
    end

interrupt click to toggle source

Interrupts the currently executing operation, causing it to abort.

    static VALUE interrupt(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      sqlite3_interrupt(ctx->db);

      return self;
    }

last_insert_row_id click to toggle source

Obtains the unique row ID of the last row to be inserted by this Database instance.

    static VALUE last_insert_row_id(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return LL2NUM(sqlite3_last_insert_rowid(ctx->db));
    }

load_extension(file) click to toggle source

Loads an SQLite extension library from the named file. Extension loading must be enabled using db.enable_load_extension(true) prior to calling this API.

    static VALUE load_extension(VALUE self, VALUE file)
    {
      sqlite3RubyPtr ctx;
      int status;
      char *errMsg;
      VALUE errexp;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      status = sqlite3_load_extension(ctx->db, RSTRING_PTR(file), 0, &errMsg);
      if (status != SQLITE_OK)
      {
        errexp = rb_exc_new2(rb_eRuntimeError, errMsg);
        sqlite3_free(errMsg);
        rb_exc_raise(errexp);
      }

      return self;
    }

prepare(sql) { |stmt| ... } click to toggle source

Returns a Statement object representing the given SQL. This does not execute the statement; it merely prepares the statement for execution.

The Statement can then be executed using SQLite3::Statement#execute.

    # File lib/sqlite3/database.rb, line 90
    def prepare sql
      stmt = SQLite3::Statement.new( self, sql )
      return stmt unless block_given?

      begin
        yield stmt
      ensure
        stmt.close unless stmt.closed?
      end
    end

query( sql, bind_vars = [], *args ) { |result| ... } click to toggle source

This is a convenience method for creating a statement, binding paramters to it, and calling execute:

    result = db.query( "select * from foo where a=?", [5])
    # is the same as
    result = db.prepare( "select * from foo where a=?" ).execute( 5 )

You must be sure to call `close` on the ResultSet instance that is returned, or you could have problems with locks on the table. If called with a block, `close` will be invoked implicitly when the block terminates.

    # File lib/sqlite3/database.rb, line 250
        def query( sql, bind_vars = [], *args )

          if bind_vars.nil? || !args.empty?
            if args.empty?
              bind_vars = []
            else
              bind_vars = [bind_vars] + args
            end

            warn("#{caller[0]} is calling SQLite3::Database#query with nil or multiple bind params
    without using an array.  Please switch to passing bind parameters as an array.
    Support for this will be removed in version 2.0.0.
    ") if $VERBOSE
          end

          result = prepare( sql ).execute( bind_vars )
          if block_given?
            begin
              yield result
            ensure
              result.close
            end
          else
            return result
          end
        end

total_changes click to toggle source

Returns the total number of changes made to this database instance since it was opened.

    static VALUE total_changes(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return INT2NUM((long)sqlite3_total_changes(ctx->db));
    }

trace { |sql| ... } click to toggle source
trace(Class.new { def call sql; end }.new)

Installs (or removes) a block that will be invoked for every SQL statement executed. The block receives one parameter: the SQL statement executed. If the block is `nil`, any existing tracer will be uninstalled.

    static VALUE trace(int argc, VALUE *argv, VALUE self)
    {
      sqlite3RubyPtr ctx;
      VALUE block;

      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      rb_scan_args(argc, argv, "01", &block);

      if(NIL_P(block) && rb_block_given_p()) block = rb_block_proc();

      rb_iv_set(self, "@tracefunc", block);

      sqlite3_trace(ctx->db, NIL_P(block) ? NULL : tracefunc, (void *)self);

      return self;
    }

transaction_active? click to toggle source

Returns `true` if there is a transaction active, and `false` otherwise.

    static VALUE transaction_active_p(VALUE self)
    {
      sqlite3RubyPtr ctx;
      Data_Get_Struct(self, sqlite3Ruby, ctx);
      REQUIRE_OPEN_DB(ctx);

      return sqlite3_get_autocommit(ctx->db) ? Qfalse : Qtrue;
    }

translator() click to toggle source

Return the type translator employed by this database instance. Each database instance has its own type translator; this allows for different type handlers to be installed in each instance without affecting other instances. Furthermore, the translators are instantiated lazily, so that if a database does not use type translation, it will not be burdened by the overhead of a useless type translator. (See the Translator class.)

    # File lib/sqlite3/database.rb, line 73
    def translator
      @translator ||= Translator.new
    end