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Overview
| Comment: | Added length() and substr() functions (CVS 143) |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
0eef538f3de66fede7c88f8be8c3458d |
| User & Date: | drh 2000-08-28 15:51:44 |
Context
|
2000-08-28
| ||
| 16:21 | adding length() and substr() tests. fix shell.c bug (CVS 144) check-in: b8cec9b9 user: drh tags: trunk | |
| 15:51 | Added length() and substr() functions (CVS 143) check-in: 0eef538f user: drh tags: trunk | |
|
2000-08-22
| ||
| 18:30 | Version 1.0.3 (CVS 497) check-in: d35a1f8b user: drh tags: trunk | |
Changes
Changes to src/expr.c.
20 20 ** drh@hwaci.com 21 21 ** http://www.hwaci.com/drh/ 22 22 ** 23 23 ************************************************************************* 24 24 ** This file contains routines used for analyzing expressions and 25 25 ** for generating VDBE code that evaluates expressions. 26 26 ** 27 -** $Id: expr.c,v 1.18 2000/06/21 13:59:11 drh Exp $ 27 +** $Id: expr.c,v 1.19 2000/08/28 15:51:44 drh Exp $ 28 28 */ 29 29 #include "sqliteInt.h" 30 30 31 31 /* 32 32 ** Walk an expression tree. Return 1 if the expression is constant 33 33 ** and 0 if it involves variables. 34 34 */ ................................................................................ 319 319 } aFunc[] = { 320 320 { "count", 5, FN_Count }, 321 321 { "min", 3, FN_Min }, 322 322 { "max", 3, FN_Max }, 323 323 { "sum", 3, FN_Sum }, 324 324 { "avg", 3, FN_Avg }, 325 325 { "fcnt", 4, FN_Fcnt }, /* Used for testing only */ 326 + { "length", 6, FN_Length}, 327 + { "substr", 6, FN_Substr}, 326 328 }; 327 329 int i; 328 330 for(i=0; i<ArraySize(aFunc); i++){ 329 331 if( aFunc[i].len==pToken->n 330 332 && sqliteStrNICmp(pToken->z, aFunc[i].zName, aFunc[i].len)==0 ){ 331 333 return aFunc[i].id; 332 334 } ................................................................................ 376 378 case FN_Avg: 377 379 case FN_Sum: { 378 380 no_such_func = !allowAgg; 379 381 too_many_args = n>1; 380 382 too_few_args = n<1; 381 383 is_agg = 1; 382 384 break; 385 + } 386 + case FN_Length: { 387 + too_few_args = n<1; 388 + too_many_args = n>1; 389 + break; 390 + } 391 + case FN_Substr: { 392 + too_few_args = n<3; 393 + too_many_args = n>3; 394 + break; 383 395 } 384 396 /* The "fcnt(*)" function always returns the number of fetch 385 397 ** operations that have occurred so far while processing the 386 398 ** SQL statement. This information can be used by test procedures 387 399 ** to verify that indices are being used properly to minimize 388 400 ** searching. All arguments to fcnt() are ignored. fcnt() has 389 401 ** no use (other than testing) that we are aware of. 390 402 */ 391 403 case FN_Fcnt: { 392 404 n = 0; 393 405 break; 394 406 } 407 + 395 408 default: break; 396 409 } 397 410 if( no_such_func ){ 398 411 sqliteSetNString(&pParse->zErrMsg, "no such function: ", -1, 399 412 pExpr->token.z, pExpr->token.n, 0); 400 413 pParse->nErr++; 401 414 nErr++; ................................................................................ 570 583 break; 571 584 } 572 585 case TK_FUNCTION: { 573 586 int id = pExpr->iColumn; 574 587 int op; 575 588 int i; 576 589 ExprList *pList = pExpr->pList; 577 - if( id==FN_Fcnt ){ 578 - sqliteVdbeAddOp(v, OP_Fcnt, 0, 0, 0, 0); 579 - break; 580 - } 581 - op = id==FN_Min ? OP_Min : OP_Max; 582 - for(i=0; i<pList->nExpr; i++){ 583 - sqliteExprCode(pParse, pList->a[i].pExpr); 584 - if( i>0 ){ 585 - sqliteVdbeAddOp(v, op, 0, 0, 0, 0); 590 + switch( id ){ 591 + case FN_Fcnt: { 592 + sqliteVdbeAddOp(v, OP_Fcnt, 0, 0, 0, 0); 593 + break; 594 + } 595 + case FN_Min: 596 + case FN_Max: { 597 + op = id==FN_Min ? OP_Min : OP_Max; 598 + for(i=0; i<pList->nExpr; i++){ 599 + sqliteExprCode(pParse, pList->a[i].pExpr); 600 + if( i>0 ){ 601 + sqliteVdbeAddOp(v, op, 0, 0, 0, 0); 602 + } 603 + } 604 + break; 605 + } 606 + case FN_Length: { 607 + sqliteExprCode(pParse, pList->a[0].pExpr); 608 + sqliteVdbeAddOp(v, OP_Strlen, 0, 0, 0, 0); 609 + break; 610 + } 611 + case FN_Substr: { 612 + for(i=0; i<pList->nExpr; i++){ 613 + sqliteExprCode(pParse, pList->a[i].pExpr); 614 + } 615 + sqliteVdbeAddOp(v, OP_Substr, 0, 0, 0, 0); 616 + break; 617 + } 618 + default: { 619 + /* Can't happen! */ 620 + break; 586 621 } 587 622 } 588 623 break; 589 624 } 590 625 case TK_SELECT: { 591 626 sqliteVdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0, 0, 0); 592 627 break;
Changes to src/sqliteInt.h.
19 19 ** Author contact information: 20 20 ** drh@hwaci.com 21 21 ** http://www.hwaci.com/drh/ 22 22 ** 23 23 ************************************************************************* 24 24 ** Internal interface definitions for SQLite. 25 25 ** 26 -** @(#) $Id: sqliteInt.h,v 1.29 2000/08/02 13:47:42 drh Exp $ 26 +** @(#) $Id: sqliteInt.h,v 1.30 2000/08/28 15:51:44 drh Exp $ 27 27 */ 28 28 #include "sqlite.h" 29 29 #include "dbbe.h" 30 30 #include "vdbe.h" 31 31 #include "parse.h" 32 32 #include <gdbm.h> 33 33 #include <stdio.h> ................................................................................ 95 95 #define FN_Unknown 0 96 96 #define FN_Count 1 97 97 #define FN_Min 2 98 98 #define FN_Max 3 99 99 #define FN_Sum 4 100 100 #define FN_Avg 5 101 101 #define FN_Fcnt 6 102 +#define FN_Length 7 103 +#define FN_Substr 8 102 104 103 105 /* 104 106 ** Forward references to structures 105 107 */ 106 108 typedef struct Column Column; 107 109 typedef struct Table Table; 108 110 typedef struct Index Index;
Changes to src/vdbe.c.
37 37 ** inplicit conversion from one type to the other occurs as necessary. 38 38 ** 39 39 ** Most of the code in this file is taken up by the sqliteVdbeExec() 40 40 ** function which does the work of interpreting a VDBE program. 41 41 ** But other routines are also provided to help in building up 42 42 ** a program instruction by instruction. 43 43 ** 44 -** $Id: vdbe.c,v 1.38 2000/08/02 12:26:29 drh Exp $ 44 +** $Id: vdbe.c,v 1.39 2000/08/28 15:51:44 drh Exp $ 45 45 */ 46 46 #include "sqliteInt.h" 47 47 #include <unistd.h> 48 48 49 49 /* 50 50 ** SQL is translated into a sequence of instructions to be 51 51 ** executed by a virtual machine. Each instruction is an instance ................................................................................ 784 784 "String", "Null", "Pop", "Dup", 785 785 "Pull", "Add", "AddImm", "Subtract", 786 786 "Multiply", "Divide", "Min", "Max", 787 787 "Like", "Glob", "Eq", "Ne", 788 788 "Lt", "Le", "Gt", "Ge", 789 789 "IsNull", "NotNull", "Negative", "And", 790 790 "Or", "Not", "Concat", "Noop", 791 + "Strlen", "Substr", 791 792 }; 792 793 793 794 /* 794 795 ** Given the name of an opcode, return its number. Return 0 if 795 796 ** there is no match. 796 797 ** 797 798 ** This routine is used for testing and debugging. ................................................................................ 3125 3126 Stringify(p, tos); 3126 3127 if( i>=0 && i<p->nSet && !SetTest(&p->aSet[i], p->zStack[tos]) ){ 3127 3128 pc = pOp->p2 - 1; 3128 3129 } 3129 3130 PopStack(p, 1); 3130 3131 break; 3131 3132 } 3133 + 3134 + /* Opcode: Length * * * 3135 + ** 3136 + ** Interpret the top of the stack as a string. Replace the top of 3137 + ** stack with an integer which is the length of the string. 3138 + */ 3139 + case OP_Strlen: { 3140 + int tos = p->tos; 3141 + int len; 3142 + if( tos<0 ) goto not_enough_stack; 3143 + Stringify(p, tos); 3144 + len = p->aStack[tos].n-1; 3145 + PopStack(p, 1); 3146 + p->tos++; 3147 + p->aStack[tos].i = len; 3148 + p->aStack[tos].flags = STK_Int; 3149 + break; 3150 + } 3151 + 3152 + /* Opcode: Substr P1 P2 * 3153 + ** 3154 + ** This operation pops between 1 and 3 elements from the stack and 3155 + ** pushes back a single element. The bottom-most element popped from 3156 + ** the stack is a string and the element pushed back is also a string. 3157 + ** The other two elements popped are integers. The integers are taken 3158 + ** from the stack only if P1 and/or P2 are 0. When P1 or P2 are 3159 + ** not zero, the value of the operand is used rather than the integer 3160 + ** from the stack. In the sequel, we will use P1 and P2 to describe 3161 + ** the two integers, even if those integers are really taken from the 3162 + ** stack. 3163 + ** 3164 + ** The string pushed back onto the stack is a substring of the string 3165 + ** that was popped. There are P2 characters in the substring. The 3166 + ** first character of the substring is the P1-th character of the 3167 + ** original string where the left-most character is 1 (not 0). If P1 3168 + ** is negative, then counting begins at the right instead of at the 3169 + ** left. 3170 + */ 3171 + case OP_Substr: { 3172 + int cnt; 3173 + int start; 3174 + int n; 3175 + char *z; 3176 + 3177 + if( pOp->p2==0 ){ 3178 + if( p->tos<0 ) goto not_enough_stack; 3179 + Integerify(p, p->tos); 3180 + cnt = p->aStack[p->tos].i; 3181 + PopStack(p, 1); 3182 + }else{ 3183 + cnt = pOp->p2; 3184 + } 3185 + if( pOp->p1==0 ){ 3186 + if( p->tos<0 ) goto not_enough_stack; 3187 + Integerify(p, p->tos); 3188 + start = p->aStack[p->tos].i; 3189 + PopStack(p, 1); 3190 + }else{ 3191 + start = pOp->p1; 3192 + } 3193 + if( p->tos<0 ) goto not_enough_stack; 3194 + Stringify(p, p->tos); 3195 + n = p->aStack[p->tos].n - 1; 3196 + if( start<0 ){ 3197 + start += n; 3198 + if( start<0 ){ 3199 + cnt += start; 3200 + start = 0; 3201 + } 3202 + } 3203 + if( cnt<0 ) cnt = 0; 3204 + if( cnt > n ){ 3205 + cnt = n; 3206 + } 3207 + z = sqliteMalloc( cnt+1 ); 3208 + if( z==0 ) goto no_mem; 3209 + strncpy(z, p->zStack[p->tos], cnt); 3210 + z[cnt] = 0; 3211 + PopStack(p, 1); 3212 + p->tos++; 3213 + p->zStack[p->tos] = z; 3214 + p->aStack[p->tos].n = cnt + 1; 3215 + p->aStack[p->tos].flags = STK_Str|STK_Dyn; 3216 + break; 3217 + } 3132 3218 3133 3219 /* An other opcode is illegal... 3134 3220 */ 3135 3221 default: { 3136 3222 sprintf(zBuf,"%d",pOp->opcode); 3137 3223 sqliteSetString(pzErrMsg, "unknown opcode ", zBuf, 0); 3138 3224 rc = SQLITE_INTERNAL;
Changes to src/vdbe.h.
23 23 ************************************************************************* 24 24 ** Header file for the Virtual DataBase Engine (VDBE) 25 25 ** 26 26 ** This header defines the interface to the virtual database engine 27 27 ** or VDBE. The VDBE implements an abstract machine that runs a 28 28 ** simple program to access and modify the underlying database. 29 29 ** 30 -** $Id: vdbe.h,v 1.11 2000/07/28 14:32:50 drh Exp $ 30 +** $Id: vdbe.h,v 1.12 2000/08/28 15:51:45 drh Exp $ 31 31 */ 32 32 #ifndef _SQLITE_VDBE_H_ 33 33 #define _SQLITE_VDBE_H_ 34 34 #include <stdio.h> 35 35 36 36 /* 37 37 ** A single VDBE is an opaque structure named "Vdbe". Only routines ................................................................................ 169 169 #define OP_Negative 83 170 170 #define OP_And 84 171 171 #define OP_Or 85 172 172 #define OP_Not 86 173 173 #define OP_Concat 87 174 174 #define OP_Noop 88 175 175 176 -#define OP_MAX 88 176 +#define OP_Strlen 89 177 +#define OP_Substr 90 178 + 179 +#define OP_MAX 90 177 180 178 181 /* 179 182 ** Prototypes for the VDBE interface. See comments on the implementation 180 183 ** for a description of what each of these routines does. 181 184 */ 182 185 Vdbe *sqliteVdbeCreate(Dbbe*); 183 186 int sqliteVdbeAddOp(Vdbe*,int,int,int,const char*,int);