build.c

sqlite-3.4.1,嵌入式数据库.是一个功能强大的开源数据库,给学习和研发以及小型公司的发展带来了全所未有的好处.

  /* Begin generating the code that will insert the table record into
  ** the SQLITE_MASTER table.  Note in particular that we must go ahead
  ** and allocate the record number for the table entry now.  Before any
  ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
  ** indices to be created and the table record must come before the 
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int lbl;
    int fileFormat;
    sqlite3BeginWriteOperation(pParse, 0, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp(v, OP_VBegin, 0, 0);
    }
#endif

    /* If the file format and encoding in the database have not been set, 
    ** set them now.
    */
    sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 1);   /* file_format */
    lbl = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_If, 0, lbl);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp(v, OP_Integer, fileFormat, 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 1);
    sqlite3VdbeAddOp(v, OP_Integer, ENC(db), 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 4);
    sqlite3VdbeResolveLabel(v, lbl);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left on the top of the stack.
    ** The rowid value is needed by the code that sqlite3EndTable will
    ** generate.
    */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( isView || isVirtual ){
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    }else
#endif
    {
      sqlite3VdbeAddOp(v, OP_CreateTable, iDb, 0);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp(v, OP_NewRowid, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    sqlite3VdbeAddOp(v, OP_Insert, 0, OPFLAG_APPEND);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
  }

  /* Normal (non-error) return. */
  return;

  /* If an error occurs, we jump here */
begin_table_error:
  sqliteFree(zName);
  return;
}

/*
** This macro is used to compare two strings in a case-insensitive manner.
** It is slightly faster than calling sqlite3StrICmp() directly, but
** produces larger code.
**
** WARNING: This macro is not compatible with the strcmp() family. It
** returns true if the two strings are equal, otherwise false.
*/
#define STRICMP(x, y) (\
sqlite3UpperToLower[*(unsigned char *)(x)]==   \
sqlite3UpperToLower[*(unsigned char *)(y)]     \
&& sqlite3StrICmp((x)+1,(y)+1)==0 )

/*
** Add a new column to the table currently being constructed.
**
** The parser calls this routine once for each column declaration
** in a CREATE TABLE statement.  sqlite3StartTable() gets called
** first to get things going.  Then this routine is called for each
** column.
*/
void sqlite3AddColumn(Parse *pParse, Token *pName){
  Table *p;
  int i;
  char *z;
  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  if( p->nCol+1>SQLITE_MAX_COLUMN ){
    sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
    return;
  }
  z = sqlite3NameFromToken(pName);
  if( z==0 ) return;
  for(i=0; i<p->nCol; i++){
    if( STRICMP(z, p->aCol[i].zName) ){
      sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
      sqliteFree(z);
      return;
    }
  }
  if( (p->nCol & 0x7)==0 ){
    Column *aNew;
    aNew = sqliteRealloc( p->aCol, (p->nCol+8)*sizeof(p->aCol[0]));
    if( aNew==0 ){
      sqliteFree(z);
      return;
    }
    p->aCol = aNew;
  }
  pCol = &p->aCol[p->nCol];
  memset(pCol, 0, sizeof(p->aCol[0]));
  pCol->zName = z;
 
  /* If there is no type specified, columns have the default affinity
  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
  ** be called next to set pCol->affinity correctly.
  */
  pCol->affinity = SQLITE_AFF_NONE;
  p->nCol++;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has
** been seen on a column.  This routine sets the notNull flag on
** the column currently under construction.
*/
void sqlite3AddNotNull(Parse *pParse, int onError){
  Table *p;
  int i;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i>=0 ) p->aCol[i].notNull = onError;
}

/*
** Scan the column type name zType (length nType) and return the
** associated affinity type.
**
** This routine does a case-independent search of zType for the 
** substrings in the following table. If one of the substrings is
** found, the corresponding affinity is returned. If zType contains
** more than one of the substrings, entries toward the top of 
** the table take priority. For example, if zType is 'BLOBINT', 
** SQLITE_AFF_INTEGER is returned.
**
** Substring     | Affinity
** --------------------------------
** 'INT'         | SQLITE_AFF_INTEGER
** 'CHAR'        | SQLITE_AFF_TEXT
** 'CLOB'        | SQLITE_AFF_TEXT
** 'TEXT'        | SQLITE_AFF_TEXT
** 'BLOB'        | SQLITE_AFF_NONE
** 'REAL'        | SQLITE_AFF_REAL
** 'FLOA'        | SQLITE_AFF_REAL
** 'DOUB'        | SQLITE_AFF_REAL
**
** If none of the substrings in the above table are found,
** SQLITE_AFF_NUMERIC is returned.
*/
char sqlite3AffinityType(const Token *pType){
  u32 h = 0;
  char aff = SQLITE_AFF_NUMERIC;
  const unsigned char *zIn = pType->z;
  const unsigned char *zEnd = &pType->z[pType->n];

  while( zIn!=zEnd ){
    h = (h<<8) + sqlite3UpperToLower[*zIn];
    zIn++;
    if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
      aff = SQLITE_AFF_TEXT; 
    }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
        && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
      aff = SQLITE_AFF_NONE;
#ifndef SQLITE_OMIT_FLOATING_POINT
    }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
    }else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a')          /* FLOA */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
    }else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b')          /* DOUB */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
#endif
    }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */
      aff = SQLITE_AFF_INTEGER;
      break;
    }
  }

  return aff;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  The pFirst token is the first
** token in the sequence of tokens that describe the type of the
** column currently under construction.   pLast is the last token
** in the sequence.  Use this information to construct a string
** that contains the typename of the column and store that string
** in zType.
*/ 
void sqlite3AddColumnType(Parse *pParse, Token *pType){
  Table *p;
  int i;
  Column *pCol;

  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i<0 ) return;
  pCol = &p->aCol[i];
  sqliteFree(pCol->zType);
  pCol->zType = sqlite3NameFromToken(pType);
  pCol->affinity = sqlite3AffinityType(pType);
}

/*
** The expression is the default value for the most recently added column
** of the table currently under construction.
**
** Default value expressions must be constant.  Raise an exception if this
** is not the case.
**
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.
*/
void sqlite3AddDefaultValue(Parse *pParse, Expr *pExpr){
  Table *p;
  Column *pCol;
  if( (p = pParse->pNewTable)!=0 ){
    pCol = &(p->aCol[p->nCol-1]);
    if( !sqlite3ExprIsConstantOrFunction(pExpr) ){
      sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
          pCol->zName);
    }else{
      Expr *pCopy;
      sqlite3ExprDelete(pCol->pDflt);
      pCol->pDflt = pCopy = sqlite3ExprDup(pExpr);
      if( pCopy ){
        sqlite3TokenCopy(&pCopy->span, &pExpr->span);
      }
    }
  }
  sqlite3ExprDelete(pExpr);
}

/*
** Designate the PRIMARY KEY for the table.  pList is a list of names 
** of columns that form the primary key.  If pList is NULL, then the
** most recently added column of the table is the primary key.
**
** A table can have at most one primary key.  If the table already has
** a primary key (and this is the second primary key) then create an
** error.
**
** If the PRIMARY KEY is on a single column whose datatype is INTEGER,
** then we will try to use that column as the rowid.  Set the Table.iPKey
** field of the table under construction to be the index of the
** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is
** no INTEGER PRIMARY KEY.
**
** If the key is not an INTEGER PRIMARY KEY, then create a unique
** index for the key.  No index is created for INTEGER PRIMARY KEYs.
*/
void sqlite3AddPrimaryKey(
  Parse *pParse,    /* Parsing context */
  ExprList *pList,  /* List of field names to be indexed */
  int onError,      /* What to do with a uniqueness conflict */
  int autoInc,      /* True if the AUTOINCREMENT keyword is present */
  int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */
){
  Table *pTab = pParse->pNewTable;
  char *zType = 0;
  int iCol = -1, i;
  if( pTab==0 || IN_DECLARE_VTAB ) goto primary_key_exit;
  if( pTab->hasPrimKey ){
    sqlite3ErrorMsg(pParse, 
      "table \"%s\" has more than one primary key", pTab->zName);
    goto primary_key_exit;
  }
  pTab->hasPrimKey = 1;
  if( pList==0 ){
    iCol = pTab->nCol - 1;
    pTab->aCol[iCol].isPrimKey = 1;
  }else{
    for(i=0; i<pList->nExpr; i++){
      for(iCol=0; iCol<pTab->nCol; iCol++){
        if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
          break;
        }
      }
      if( iCol<pTab->nCol ){
        pTab->aCol[iCol].isPrimKey = 1;
      }
    }
    if( pList->nExpr>1 ) iCol = -1;
  }
  if( iCol>=0 && iCol<pTab->nCol ){
    zType = pTab->aCol[iCol].zType;
  }
  if( zType && sqlite3StrICmp(zType, "INTEGER")==0
        && sortOrder==SQLITE_SO_ASC ){
    pTab->iPKey = iCol;
    pTab->keyConf = onError;
    pTab->autoInc = autoInc;
  }else if( autoInc ){
#ifndef SQLITE_OMIT_AUTOINCREMENT
    sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
       "INTEGER PRIMARY KEY");
#endif
  }else{
    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
    pList = 0;
  }

primary_key_exit:
  sqlite3ExprListDelete(pList);
  return;
}

/*
** Add a new CHECK constraint to the table currently under construction.
*/
void sqlite3AddCheckConstraint(
  Parse *pParse,    /* Parsing context */
  Expr *pCheckExpr  /* The check expression */
){
#ifndef SQLITE_OMIT_CHECK
  Table *pTab = pParse->pNewTable;
  if( pTab && !IN_DECLARE_VTAB ){
    /* The CHECK expression must be duplicated so that tokens refer
    ** to malloced space and not the (ephemeral) text of the CREATE TABLE
    ** statement */
    pTab->pCheck = sqlite3ExprAnd(pTab->pCheck, sqlite3ExprDup(pCheckExpr));
  }
#endif
  sqlite3ExprDelete(pCheckExpr);
}

/*
** Set the collation function of the most recently parsed table column
** to the CollSeq given.
*/
void sqlite3AddCollateType(Parse *pParse, const char *zType, int nType){
  Table *p;
  int i;

  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;

  if( sqlite3LocateCollSeq(pParse, zType, nType) ){
    Index *pIdx;
    p->aCol[i].zColl = sqliteStrNDup(zType, nType);
  
    /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
    ** then an index may have been created on this column before the
    ** collation type was added. Correct this if it is the case.
    */
    for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->nColumn==1 );
      if( pIdx->aiColumn[0]==i ){
        pIdx->azColl[0] = p->aCol[i].zColl;
      }
    }
  }
}

/*
** This function returns the collation sequence for database native text
** encoding identified by the string zName, length nName.
**
** If the requested collation sequence is not available, or not available
** in the database native encoding, the collation factory is invoked to
** request it. If the collation factory does not supply such a sequence,
** and the sequence is available in another text encoding, then that is
** returned instead.
**
** If no versions of the requested collations sequence are available, or
** another error occurs, NULL is returned and an error message written into
** pParse.
**
** This routine is a wrapper around sqlite3FindCollSeq().  This routine
** invokes the collation factory if the named collation cannot be found
** and generates an error message.
*/
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName){
  sqlite3 *db = pParse->db;
  u8 enc = ENC(db);
  u8 initbusy = db->init.busy;
  CollSeq *pColl;

  pColl = sqlite3FindCollSeq(db, enc, zName, nName, initbusy);
  if( !initbusy && (!pColl || !pColl->xCmp) ){
    pColl = sqlite3GetCollSeq(db, pColl, zName, nName);
    if( !pColl ){
      if( nName<0 ){
        nName = strlen(zName);
      }