annotate CHANGELOG @ 1923:afdc823563de

Small reformatting and documentation for '-print-cinclude'
author Adam Chlipala <adam@chlipala.net>
date Fri, 06 Dec 2013 08:54:03 -0500
parents 7d26b96370af
children b3c8860508ea
rev   line source
adam@1911 1 ========
adam@1911 2 20131124
adam@1911 3 ========
adam@1911 4
adam@1911 5 - Extend 'where con' to allow descending into submodule structure
adam@1911 6 - Type inference improvements
adam@1911 7 - Treat transactional FFI functions as effectful by default,
adam@1911 8 so that 'effectful'/'benignEffectful' .urp directives aren't necessary
adam@1911 9 - Interpret 'table' signature items more flexibly,
adam@1911 10 automatically adding (Ur) constraints to support
adam@1911 11 a kind of subtyping over (SQL) constraint sets
adam@1911 12 - New header file scheme to support FFI code in either of C or C++
adam@1911 13 - New command-line arguments: -ccompiler, -print-ccompiler
adam@1911 14 - More HTML tags: <dd>, <dl>, <dt>, <em>, and <strong>
adam@1911 15 - Add 'rel' attribute to <a>
adam@1911 16 - New type synonym 'xhead'
adam@1911 17 - Refactored the development Mercurial repository to remove autogenerated files
adam@1911 18 - More integration with Autotools distribution functionality
adam@1911 19 - Improvements to documentation and compiler error messages
adam@1911 20 - Bug fixes and optimization improvements
adam@1911 21
adam@1851 22 ========
adam@1851 23 20130421
adam@1851 24 ========
adam@1851 25
adam@1851 26 - Allow any FFI module to declare new HTML tags
adam@1851 27 - Ignore polymorphism in JavaScript calls to custom FFI functions, allowing a
adam@1851 28 kind of simple dynamic typing (unsafe, of course)
adam@1851 29 - Add some name-mangling rules to allow XML attribute 'name' and attributes with
adam@1851 30 dashes
adam@1851 31 - New Basis members: pow and tryRpc
adam@1851 32 - Add 'placeholder' attribute for <password>
adam@1851 33 - New standard library functions: Option.unsafeGet
adam@1851 34 - Add ./configure MLTONARGS option for MLTON arguments
adam@1851 35 - Bug fixes and documentation improvements
adam@1851 36
adam@1826 37 ========
adam@1826 38 20120925
adam@1826 39 ========
adam@1826 40
adam@1826 41 - Changes to optimization/compilation strategy that can speed up compilation and
adam@1826 42 reduce code size dramatically
adam@1826 43 - New .urp directives: 'coreInline' and 'monoInline'
adam@1826 44 - 'show' instance for 'sql_query'
adam@1826 45 - Improvements to compiler error messages
adam@1826 46 - Bug fixes and optimization improvements
adam@1826 47
adam@1806 48 ========
adam@1806 49 20120807
adam@1806 50 ========
adam@1806 51
adam@1806 52 - Client-side mouse and keyboard event handlers are now functions over records.
adam@1806 53 - More flexibility in local type class instances
adam@1806 54 - Remove 'class' declaration; use 'con' instead now.
adam@1806 55 - SQL window functions
adam@1806 56 - New HTML pseudo-tag: <active>
adam@1806 57 - New Basis members: getenv (and associated functions), giveFocus
adam@1806 58 - New Top member: postFields (to process POST form data when called by some external script)
adam@1806 59 - HTTP daemons take '-a' option to set IP address to listen on
adam@1806 60 - More global mouse event hooks
adam@1806 61 - Bug fixes and performance improvements
adam@1806 62
adam@1771 63 ========
adam@1771 64 20120519
adam@1771 65 ========
adam@1771 66
adam@1771 67 - Compatibility fixes for new Automake and GCC versions
adam@1771 68 - Allow synchronous RPC's in 'onunload' code
adam@1771 69 - Start of special cases for parsing CSS class names: interpret "table" as identifier 'tabl'
adam@1771 70 (since 'table' is an Ur/Web keyword)
adam@1771 71 - Bug fixes and improvements to type inference and optimization
adam@1771 72
adam@1758 73 ========
adam@1758 74 20120512
adam@1758 75 ========
adam@1758 76
adam@1758 77 - New support for CSS style code embedded in Ur/Web programs.
adam@1758 78 Two recommended usage methods:
adam@1758 79 1. Use 'style' attributes with normal CSS syntax inside string literals.
adam@1758 80 2. Generate styles programmatically with the Style module of the Gui library
adam@1758 81 (distributed separately).
adam@1758 82 - 'dynStyle' attribute, which is to 'style' as 'dynClass' is to 'class'
adam@1758 83 - Parsing of standard syntax for 'class' attributes, via specially interpreted
adam@1758 84 string literals
adam@1758 85 - New optional suffix for 'rewrite' in .urp files: [-]
adam@1758 86 - Compiler error message improvements, including simplification of types
adam@1758 87 - New command line parameters: '-boot', '-dumpTypesOnError', '-unifyMore'
adam@1758 88 - New .urp directives: 'linker'
adam@1758 89 - Support for speeding up compilation by caching type inference results:
adam@1758 90 Run 'urweb daemon start' to spawn a background process,
adam@1758 91 'urweb daemon stop' to kill it.
adam@1758 92 - Enforcement of uniqueness of top-level module names across a project
adam@1758 93 - Adjust error message format to match Emacs compilation mode defaults
adam@1758 94 - More HTML attributes added
adam@1758 95 - New antiquote syntax for 'PRIMARY KEY'
adam@1758 96 - Bug fixes and improvements to type inference and platform compatibility
adam@1758 97
adam@1705 98 ========
adam@1705 99 20120329
adam@1705 100 ========
adam@1705 101
adam@1705 102 - New JavaScript FFI function: setInnerHTML
adam@1705 103 - Bug fixes
adam@1705 104 - Documentation improvements
adam@1705 105
adam@1693 106 ========
adam@1693 107 20120310
adam@1693 108 ========
adam@1693 109
adam@1693 110 - 'ORDER BY RANDOM'
adam@1693 111 - New Basis members: diffInMilliseconds, toMilliseconds
adam@1693 112 - <radio> widget now returns 'option string' instead of 'string'
adam@1693 113 - '-dumpSource' command-line flag
adam@1693 114 - Bug fixes and optimization improvements
adam@1693 115
adam@1669 116 ========
adam@1669 117 20120110
adam@1669 118 ========
adam@1669 119
adam@1669 120 - Improvements to type inference and error messages
adam@1669 121 - New 'dynClass' pseudo-attribute for most HTML tags
adam@1669 122 - New 't.*' notation for selecting all columns of a table
adam@1669 123 - New SQL functions: 'lower' and 'upper'
adam@1669 124 - 'timeFormat' .urp directive
adam@1669 125 - Client-side 'debug' and 'naughtyDebug' calls use a browser debug console, if available
adam@1669 126 - Allow 'source' values to be returned by RPCs
adam@1669 127 - Change the HTML context classification scheme in 'Basis'
adam@1669 128 - Rename 'Top.id' to 'ident' to avoid clash with 'Basis.id'
adam@1669 129 - More client-side function implementations
adam@1669 130 - Some expanded reference manual sections
adam@1669 131 - Tweak to linker command line argument order (to prevent issues with new Ubuntu versions)
adam@1669 132 - Bug fixes
adam@1669 133
adam@1616 134 ========
adam@1616 135 20111127
adam@1616 136 ========
adam@1616 137
adam@1616 138 - Improvements to type inference and error messages
adam@1616 139 - New Basis members: ceil, float, null, round, trunc
adam@1616 140 - New SQL expression forms: 'IF..THEN..ELSE', 'COALESCE', and 'LIKE'
adam@1616 141 - Support for the full set of HTML character entities
adam@1616 142 - Client-side versions of some time-related functions
adam@1616 143 - New URWEB_PG_CON environment variable
adam@1616 144 - Allow arguments for 'con' signature items, not just declarations
adam@1616 145 - Bug fixes and performance improvements
adam@1616 146 - Tweaks for idiosyncrasies of OS X (like deprecated OpenSSL)
adam@1616 147
adam@1509 148 ========
adam@1561 149 20110917
adam@1509 150 ========
adam@1509 151
adam@1509 152 - Start of official tutorial
adam@1509 153 - Compiler support for generating nice tutorial HTML from literate source files
adam@1509 154 - New protocol 'static' for generating static pages
adam@1561 155 - Replace GCCARGS 'configure' variable with CCARGS
adam@1561 156 - Better support for compilation with Clang (including on OS X)
adam@1561 157 - Fancier 'configure' script with versioning
adam@1523 158 - Applications consult URWEB_STACK_SIZE environment variable to determine thread
adam@1523 159 stack size
adam@1561 160 - HTML tag IDs now drawn from an abstract type
adam@1561 161 - New Basis functions: diffInSeconds, mkMonad, onClick, onDblclick, onKeydown,
adam@1561 162 onKeypress, onKeyup, onMousedown, onMouseup, preventDefault, stopPropagation,
adam@1561 163 toSeconds
adam@1561 164 - Add <image> tag
adam@1561 165 - Add 'target' attribute for <a>
adam@1561 166 - New compiler command-line option: -dumpTypes
adam@1561 167 - New syntactic sugar for computed ORDER BY clauses
adam@1561 168 - Bug fixes and optimization improvements
adam@1509 169
adam@1492 170 ========
adam@1492 171 20110715
adam@1492 172 ========
adam@1492 173
adam@1492 174 - Treat local variables the same as module-level variables, for the purpose of
adam@1492 175 implicit argument insertion
adam@1492 176 - New 'noXsrfProtection' directive for .urp files
adam@1492 177 - Non-debug builds omit source location information in error messages shown to
adam@1492 178 the user (but keep that information in log entries)
adam@1492 179 - Basis.getHeader and Basis.setHeader
adam@1492 180 - Basis.show_css_class
adam@1492 181 - Basis.currentUrlHasQueryString
adam@1492 182 - Make Basis.rand cryptographically secure
adam@1492 183 - Client-side versions of Basis.now and Basis.show_time
adam@1492 184 - Bug fixes
adam@1492 185 - Improvements to auto-configuration and build process (now builds with LLVM's
adam@1492 186 Clang!)
adam@1492 187 - Clarifications in the manual
adam@1492 188
adam@1458 189 ========
adam@1460 190 20110517
adam@1458 191 ========
adam@1458 192
adam@1458 193 - Cygwin compatibility
adam@1458 194 - Compatibility with Gentoo packaging process, including a .ebuild file
adam@1458 195 - Change typing of SQL subqueries, to indicate that they may always return NULL
adam@1458 196 (for no rows)
adam@1458 197 - Syntactic sugar for GROUP BY with variable numbers of columns
adam@1458 198 (using 'tab.{{c}}', where 'c :: {Type}')
adam@1458 199 - 'ALL' for SQL relational operators
adam@1458 200 - Add nullable types to the class for valid operands for SQL arithmetic
adam@1458 201 - 'alt' attribute for <img>
adam@1458 202 - <sup> and <sub> HTML tags
adam@1458 203 - Allow 'debug' and 'naughtyDebug' in client-side code, implemented with 'alert'
adam@1458 204 - Bug fixes and optimization improvements
adam@1458 205
adam@1400 206 ========
adam@1414 207 20110123
adam@1400 208 ========
adam@1400 209
adam@1400 210 - Changes to encoding of SQL aggregate functions: nullable types may be
adam@1400 211 aggregated, and non-COUNT aggregates return nullable results.
adam@1400 212 - SQL subqueries may apply aggregate functions to columns bound in enclosing
adam@1400 213 queries.
adam@1400 214 - Switch from libmhash to OpenSSL.
adam@1400 215 - 'cdataChar', for injecting arbitrary character codes into XML
adam@1400 216 - 'crypt', for access to the standard UNIX password encryption routine
adam@1400 217 - 'readUtc', for parsing time strings in the UTC time zone
adam@1400 218 - Built-in 'time' type now stores microseconds (which for now are only used in
adam@1400 219 connection with Postgres timestamps).
adam@1400 220 - Client-side URL blessing and redirection
adam@1400 221 - 'currentUrlHasPost' function
adam@1400 222 - Transactional 'free' functions now passed an argument indicating whether the
adam@1400 223 runtime system expects to retry the transaction.
adam@1400 224 - Change tasks to allow task kind-specific inputs
adam@1400 225 - Add 'clientLeaves' and 'periodic' task kinds
adam@1400 226 - Support for externally-callable pages, via the 'postBody' and 'queryString'
adam@1400 227 types and the 'effectfulUrl' function
adam@1400 228 - 'minHeap' and 'alwaysInline' .urp options
adam@1400 229 - '-prefix' command-line option
adam@1400 230 - Comments in .urp files (lines starting with '#')
adam@1400 231 - Miscellaneous additions to the standard library
adam@1400 232 - Bug fixes and improvements to type inference and optimization
adam@1400 233
adam@1287 234 ========
adam@1315 235 20101102
adam@1287 236 ========
adam@1287 237
adam@1287 238 - Polymorphic variants (see Basis.variant)
adam@1297 239 - New 'onError' directive for .urp files
adam@1287 240 - (* *) and <!-- --> comments in XML
adam@1297 241 - Basis.classes, Basis.confirm, and Basis.tryDml
adam@1309 242 - New notations ::_ and :::_, for constructor parameters of unknown kind
adam@1297 243 - Invocations like 'urweb foo' will compile foo.ur as a single-file project,
adam@1297 244 even if no foo.urp exists
adam@1309 245 - '-limit' command-line flag and 'limit' .urp directive
adam@1297 246 - Bug fixes and optimization improvements
adam@1287 247
adamc@1259 248 ========
adamc@1273 249 20100603
adamc@1259 250 ========
adamc@1259 251
adamc@1259 252 - Changed URL escaping convention, to avoid confusing proxies.
adamc@1259 253 The new convention is like the normal one, but with '.' instead of '%'.
adamc@1261 254 - Changed JavaScript compilation of recursive functions to use thunks.
adamc@1261 255 This change avoids most costs of functions not referenced on particular
adamc@1261 256 pages, reducing loading time dramatically.
adamc@1273 257 - Support HTTP caching of application-specific JavaScript code
adamc@1273 258 - Bug fixes
adamc@1259 259
adamc@1255 260 ========
adamc@1255 261 20100506
adamc@1255 262 ========
adamc@1255 263
adamc@1255 264 - New experimental checker for information flow and access control policies
adamc@1255 265 (See demo at http://www.impredicative.com/ur/scdv/)
adamc@1255 266
adamc@1197 267 ========
adamc@1197 268 20100401
adamc@1197 269 ========
adamc@1197 270
adamc@1197 271 - Subquery expressions and FROM items
adamc@1197 272 - Low-level support for SELECT with no FROM clause
adamc@1197 273 - Fixes for DBMS-portability of relational operators
adamc@1197 274
adamc@1183 275 ========
adamc@1190 276 20100325
adamc@1183 277 ========
adamc@1183 278
adamc@1188 279 - -verbose flag
adamc@1188 280 - COUNT(col) SQL aggregate function
adamc@1188 281 - 'benignEffectful' and 'safeGet' .urp commands
adamc@1188 282 - Remove Basis.getRequestHeader, since it can be used to circumvent cookie
adamc@1188 283 security
adamc@1190 284 - Rename Top.foldR*X to map*X
adamc@1188 285 - Bug fixes and optimization improvements
adamc@1183 286
adamc@1166 287 ========
adamc@1166 288 20100213
adamc@1166 289 ========
adamc@1166 290
adamc@1166 291 - Improvements to 'configure'; should now fail if any uncommon but required
adamc@1166 292 package is missing
adamc@1166 293 - Other fixes to configuration, build system, and C code portability
adamc@1166 294 - sigfile .urp directive & -sigfile command-line option
adamc@1166 295 - .urp files with no directives no longer need to begin with blank lines.
adamc@1166 296 - Other bug fixes
adamc@1166 297
adamc@1137 298 ========
adamc@1137 299 20100130
adamc@1137 300 ========
adamc@1137 301
adamc@1137 302 - Conversion to an Automake-based build system, for greater portability in
adamc@1137 303 building shared libraries
adamc@1137 304 - -path and -root command-line flags
adamc@1137 305 - Exported page handling functions (i.e., those page-generating functions
adamc@1137 306 appearing in the main module's signature) may now take any number of
adamc@1137 307 arguments, including 0.
adamc@1137 308
adamc@1123 309 ========
adamc@1123 310 20100112
adamc@1123 311 ========
adamc@1123 312
adamc@1123 313 - Basis.serialized type family, for storing more types in the database
adamc@1123 314 - Basis.textBlob, for building blobs from strings
adamc@1123 315 - Basis.debug function, for server-side debug printing
adamc@1123 316 - Bug fixes & optimization improvements
adamc@1123 317
adamc@1065 318 ========
adamc@1103 319 20091230
adamc@1065 320 ========
adamc@1065 321
adamc@1093 322 - Automatic insertion of implicit arguments in more positions
adamc@1065 323 - Reifying expressions as URLs and redirecting to them explicitly
adamc@1070 324 - More syntactic sugar for SQL
adamc@1070 325 - Typing of SQL queries no longer exposes which tables were used in joins but
adamc@1070 326 had none of their fields projected
adamc@1075 327 - Tasks
adamc@1095 328 - Dynamic linking of the runtime system
adamc@1077 329 - Optimization improvements
adamc@1103 330 - Bug fixes
adamc@1065 331
adamc@1050 332 ========
adamc@1056 333 20091203
adamc@1050 334 ========
adamc@1050 335
adamc@1050 336 - Extended cookie interface (breaks backward compatibility for 'setCookie')
adamc@1050 337 - Bug fixes
adamc@1056 338 - Extended UTF-8 characters in HTML
adamc@1050 339
adamc@1043 340 ========
adamc@1043 341 20091124
adamc@1043 342 ========
adamc@1043 343
adamc@1043 344 - Improved Internet Explorer compatibility
adamc@1043 345
adamc@1020 346 ========
adamc@1033 347 20091108
adamc@1020 348 ========
adamc@1020 349
adamc@1020 350 - Bug fixes
adamc@1020 351 - Optimization improvements
adamc@1021 352 - Removed a restriction that prevented some RPCs and calls to sleep or recv
adamc@1021 353 from compiling
adamc@1020 354
adamc@999 355 ========
adamc@999 356 20091012
adamc@999 357 ========
adamc@999 358
adamc@999 359 - Small bug fixes affecting MySQL and SQLite
adamc@999 360
adamc@988 361 ========
adamc@997 362 20091009
adamc@988 363 ========
adamc@988 364
adamc@988 365 - Bug fixes
adamc@988 366 - Improvement to choice of line number to cite in record unification error
adamc@988 367 messages
adamc@994 368 - SELECT DISTINCT
adamc@996 369 - New extra demos: orm1 and versioned1
adamc@988 370
adamc@985 371 ========
adamc@985 372 20090926
adamc@985 373 ========
adamc@985 374
adamc@985 375 - Reimplemented client-side code generation to use an interpreter, rather than
adamc@985 376 compilation to JavaScript; this avoids common browser flaws: lack of
adamc@985 377 optimization of tail calls and occasional bugs in closure handling.
adamc@985 378 - Bug fixes
adamc@985 379
adamc@968 380 ========
adamc@968 381 20090919
adamc@968 382 ========
adamc@968 383
adamc@968 384 - Bug fixes
adamc@968 385 - Optimization improvements
adamc@968 386 - Expanded grid demo in demo/more: optional columns, sorting, filtering,
adamc@968 387 paging, selecting rows, aggregate row
adamc@968 388
adamc@929 389 ========
adamc@929 390 20090912
adamc@929 391 ========
adamc@929 392
adamc@929 393 - Bug fixes
adamc@929 394 - Optimization improvements
adamc@929 395 - New set of extra demos in demo/more
adamc@929 396
adamc@914 397 ========
adamc@914 398 20090825
adamc@914 399 ========
adamc@914 400
adamc@914 401 - Many bug fixes
adamc@914 402 - Remote procedure calls must be marked with the new 'rpc' function.
adamc@914 403 - Some tweaks to enable usage on OSX (suggested by Paul Snively)
adamc@914 404
adamc@897 405 ========
adamc@897 406 20090718
adamc@897 407 ========
adamc@897 408
adamc@897 409 - New application protocols: CGI and FastCGI
adamc@897 410 - New database backends: MySQL and SQLite
adamc@897 411 - More JavaScript events added to tags in standard library
adamc@897 412 - New manual section on using the foreign function interface (FFI)
adamc@897 413
adamc@852 414 ========
adamc@852 415 20090623
adamc@852 416 ========
adamc@852 417
adamc@852 418 - Many bug fixes
adamc@852 419 - Mutually-recursive datatypes
adamc@852 420 - SML-style pattern-matching syntax for "fun", "fn", and local "val"
adamc@852 421 - Backwards-incompatible change to syntax of formal constructor parameters to
adamc@852 422 value-level functions, to support the previous change
adamc@852 423 - Path map support inspired by SML/NJ CM and MLton ML Basis
adamc@852 424 - Start of some new standard library modules
adamc@852 425 - Some improvements to JavaScript runtime, including better error handling
adamc@852 426
adamc@716 427 ========
adamc@790 428 20090505
adamc@716 429 ========
adamc@716 430
adamc@716 431 - Reimplement constructor class resolution to be more general and Prolog-like
adamc@716 432 - SQL table constraints
adamc@770 433 - URLs
adamc@736 434 - Client-side error handling callbacks
adamc@736 435 - CSS
adamc@736 436 - Signing cookie values cryptographically to thwart cross site request forgery
adamc@744 437 - Blobs and HTTP file upload
adamc@752 438 - SQL outer joins
adamc@755 439 - SQL views
adamc@756 440 - Subforms
adamc@768 441 - C and JavaScript FFI
adamc@768 442 - Path rewriting
adamc@716 443
adamc@702 444 ========
adamc@702 445 20090405
adamc@702 446 ========
adamc@702 447
adamc@702 448 - Asynchronous message-passing and the associated server-side client
adamc@702 449 bookkeeping
adamc@702 450 - Reimplement parts of the client-side runtime system to avoid space leaks
adamc@702 451 - spawn and sleep
adamc@702 452 - Expand the constructor class instance rule format
adamc@702 453
adamc@663 454 ========
adamc@663 455 20090312
adamc@663 456 ========
adamc@663 457
adamc@663 458 - Replace type-level "fold" with "map"
adamc@663 459 - Replace expression-level "fold" with folders, defined in Top and
adamc@663 460 supported by some special compiler inference
adamc@663 461 - Replace guarded constructors with guarded types, introduced only by
adamc@663 462 guarded expression abstraction, and with a new explicit application form
adamc@663 463 - Kind polymorphism
adamc@663 464 - Generalize type classes to constructor classes
adamc@663 465 - Initial compilation of client-side code to JavaScript
adamc@663 466 - Initial support for mixed client- and server-side programming (i.e., "AJAX")
adamc@665 467 - src/coq: Coq formalization of a core Ur-like calculus
adamc@663 468
adamc@506 469 ========
adamc@561 470 20081209
adamc@506 471 ========
adamc@506 472
adamc@506 473 - Optimization: Fusing page writes with calls to recursive functions
adamc@523 474 - Optimization of bottleneck compiler phases
adamc@561 475 - Reference manual
adamc@561 476 - SQL arithmetic operators
adamc@506 477
adamc@504 478 ========
adamc@504 479 20081120
adamc@504 480 ========
adamc@504 481
adamc@504 482 - Fix bug that sometimes led to omission of initial "<html>" in pages
adamc@504 483 - Take advantage of nested functions in some demos
adamc@504 484 - "profile" option that may appear in .urp files, to enable gprof profiling
adamc@663 485 - "-guided-demo" option that works like "-demo" but uses less screen space for
adamc@663 486 prose
adamc@504 487
adamc@467 488 ========
adamc@497 489 20081118
adamc@467 490 ========
adamc@467 491
adamc@467 492 - Nested function definitions
adamc@467 493 - Primitive "time" type
adamc@467 494 - Nullable SQL columns (via "option")
adamc@467 495 - Cookies
adamc@663 496 - Compiler: Specialization of functions to known arguments (especially of
adamc@663 497 function type)
adamc@467 498
adamc@435 499 ========
adamc@435 500 20081028
adamc@435 501 ========
adamc@435 502
adamc@435 503 - Add GCCARGS configure option
adamc@435 504
adamc@433 505 ========
adamc@433 506 20081027
adamc@433 507 ========
adamc@433 508
adamc@433 509 - On missing inputs, print an error message, but don't exit the web server.
adamc@434 510 - Remove need for "() <-" notation.
adamc@433 511
adamc@433 512 ========
adamc@433 513 20081026
adamc@433 514 ========
adamc@433 515
adamc@433 516 - Change 'sed' call to work on OSX.
adamc@433 517 - Avoid including or linking libpq files on apps that don't use SQL.