build.c

sqlite数据库管理系统开放源码

  Parse *pParse,   /* Parser context */
  Token *pStart,   /* The "CREATE" token */
  Token *pName,    /* Name of table or view to create */
  int isTemp,      /* True if this is a TEMP table */
  int isView       /* True if this is a VIEW */
){
  Table *pTable;
  Index *pIdx;
  char *zName;
  sqlite *db = pParse->db;
  Vdbe *v;
  int iDb;

  pParse->sFirstToken = *pStart;
  zName = sqliteTableNameFromToken(pName);
  if( zName==0 ) return;
  if( db->init.iDb==1 ) isTemp = 1;
#ifndef SQLITE_OMIT_AUTHORIZATION
  assert( (isTemp & 1)==isTemp );
  {
    int code;
    char *zDb = isTemp ? "temp" : "main";
    if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      sqliteFree(zName);
      return;
    }
    if( isView ){
      if( isTemp ){
        code = SQLITE_CREATE_TEMP_VIEW;
      }else{
        code = SQLITE_CREATE_VIEW;
      }
    }else{
      if( isTemp ){
        code = SQLITE_CREATE_TEMP_TABLE;
      }else{
        code = SQLITE_CREATE_TABLE;
      }
    }
    if( sqliteAuthCheck(pParse, code, zName, 0, zDb) ){
      sqliteFree(zName);
      return;
    }
  }
#endif
 

  /* Before trying to create a temporary table, make sure the Btree for
  ** holding temporary tables is open.
  */
  if( isTemp && db->aDb[1].pBt==0 && !pParse->explain ){
    int rc = sqliteBtreeFactory(db, 0, 0, MAX_PAGES, &db->aDb[1].pBt);
    if( rc!=SQLITE_OK ){
      sqliteErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->nErr++;
      return;
    }
    if( db->flags & SQLITE_InTrans ){
      rc = sqliteBtreeBeginTrans(db->aDb[1].pBt);
      if( rc!=SQLITE_OK ){
        sqliteErrorMsg(pParse, "unable to get a write lock on "
          "the temporary database file");
        return;
      }
    }
  }

  /* Make sure the new table name does not collide with an existing
  ** index or table name.  Issue an error message if it does.
  **
  ** If we are re-reading the sqlite_master table because of a schema
  ** change and a new permanent table is found whose name collides with
  ** an existing temporary table, that is not an error.
  */
  pTable = sqliteFindTable(db, zName, 0);
  iDb = isTemp ? 1 : db->init.iDb;
  if( pTable!=0 && (pTable->iDb==iDb || !db->init.busy) ){
    sqliteErrorMsg(pParse, "table %T already exists", pName);
    sqliteFree(zName);
    return;
  }
  if( (pIdx = sqliteFindIndex(db, zName, 0))!=0 &&
          (pIdx->iDb==0 || !db->init.busy) ){
    sqliteErrorMsg(pParse, "there is already an index named %s", zName);
    sqliteFree(zName);
    return;
  }
  pTable = sqliteMalloc( sizeof(Table) );
  if( pTable==0 ){
    sqliteFree(zName);
    return;
  }
  pTable->zName = zName;
  pTable->nCol = 0;
  pTable->aCol = 0;
  pTable->iPKey = -1;
  pTable->pIndex = 0;
  pTable->iDb = iDb;
  if( pParse->pNewTable ) sqliteDeleteTable(db, pParse->pNewTable);
  pParse->pNewTable = pTable;

  /* 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 = sqliteGetVdbe(pParse))!=0 ){
    sqliteBeginWriteOperation(pParse, 0, isTemp);
    if( !isTemp ){
      sqliteVdbeAddOp(v, OP_Integer, db->file_format, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 1);
    }
    sqliteOpenMasterTable(v, isTemp);
    sqliteVdbeAddOp(v, OP_NewRecno, 0, 0);
    sqliteVdbeAddOp(v, OP_Dup, 0, 0);
    sqliteVdbeAddOp(v, OP_String, 0, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, 0, 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.  sqliteStartTable() gets called
** first to get things going.  Then this routine is called for each
** column.
*/
void sqliteAddColumn(Parse *pParse, Token *pName){
  Table *p;
  int i;
  char *z = 0;
  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  sqliteSetNString(&z, pName->z, pName->n, 0);
  if( z==0 ) return;
  sqliteDequote(z);
  for(i=0; i<p->nCol; i++){
    if( sqliteStrICmp(z, p->aCol[i].zName)==0 ){
      sqliteErrorMsg(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 ) return;
    p->aCol = aNew;
  }
  pCol = &p->aCol[p->nCol];
  memset(pCol, 0, sizeof(p->aCol[0]));
  pCol->zName = z;
  pCol->sortOrder = SQLITE_SO_NUM;
  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 sqliteAddNotNull(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;
}

/*
** 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 sqliteAddColumnType(Parse *pParse, Token *pFirst, Token *pLast){
  Table *p;
  int i, j;
  int n;
  char *z, **pz;
  Column *pCol;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i<0 ) return;
  pCol = &p->aCol[i];
  pz = &pCol->zType;
  n = pLast->n + Addr(pLast->z) - Addr(pFirst->z);
  sqliteSetNString(pz, pFirst->z, n, 0);
  z = *pz;
  if( z==0 ) return;
  for(i=j=0; z[i]; i++){
    int c = z[i];
    if( isspace(c) ) continue;
    z[j++] = c;
  }
  z[j] = 0;
  if( pParse->db->file_format>=4 ){
    pCol->sortOrder = sqliteCollateType(z, n);
  }else{
    pCol->sortOrder = SQLITE_SO_NUM;
  }
}

/*
** The given token is the default value for the last column added to
** the table currently under construction.  If "minusFlag" is true, it
** means the value token was preceded by a minus sign.
**
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.
*/
void sqliteAddDefaultValue(Parse *pParse, Token *pVal, int minusFlag){
  Table *p;
  int i;
  char **pz;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i<0 ) return;
  pz = &p->aCol[i].zDflt;
  if( minusFlag ){
    sqliteSetNString(pz, "-", 1, pVal->z, pVal->n, 0);
  }else{
    sqliteSetNString(pz, pVal->z, pVal->n, 0);
  }
  sqliteDequote(*pz);
}

/*
** 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 row id.  (Exception:
** For backwards compatibility with older databases, do not do this
** if the file format version number is less than 1.)  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 sqliteAddPrimaryKey(Parse *pParse, IdList *pList, int onError){
  Table *pTab = pParse->pNewTable;
  char *zType = 0;
  int iCol = -1, i;
  if( pTab==0 ) goto primary_key_exit;
  if( pTab->hasPrimKey ){
    sqliteErrorMsg(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->nId; i++){
      for(iCol=0; iCol<pTab->nCol; iCol++){
        if( sqliteStrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ) break;
      }
      if( iCol<pTab->nCol ) pTab->aCol[iCol].isPrimKey = 1;
    }
    if( pList->nId>1 ) iCol = -1;
  }
  if( iCol>=0 && iCol<pTab->nCol ){
    zType = pTab->aCol[iCol].zType;
  }
  if( pParse->db->file_format>=1 && 
           zType && sqliteStrICmp(zType, "INTEGER")==0 ){
    pTab->iPKey = iCol;
    pTab->keyConf = onError;
  }else{
    sqliteCreateIndex(pParse, 0, 0, pList, onError, 0, 0);
    pList = 0;
  }

primary_key_exit:
  sqliteIdListDelete(pList);
  return;
}

/*
** Return the appropriate collating type given a type name.
**
** The collation type is text (SQLITE_SO_TEXT) if the type
** name contains the character stream "text" or "blob" or
** "clob".  Any other type name is collated as numeric
** (SQLITE_SO_NUM).
*/
int sqliteCollateType(const char *zType, int nType){
  int i;
  for(i=0; i<nType-3; i++){
    int c = *(zType++) | 0x60;
    if( (c=='b' || c=='c') && sqliteStrNICmp(zType, "lob", 3)==0 ){
      return SQLITE_SO_TEXT;
    }
    if( c=='c' && sqliteStrNICmp(zType, "har", 3)==0 ){
      return SQLITE_SO_TEXT;
    }
    if( c=='t' && sqliteStrNICmp(zType, "ext", 3)==0 ){
      return SQLITE_SO_TEXT;
    }
  }
  return SQLITE_SO_NUM;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  A "COLLATE" clause has
** been seen on a column.  This routine sets the Column.sortOrder on
** the column currently under construction.
*/
void sqliteAddCollateType(Parse *pParse, int collType){
  Table *p;
  int i;
  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;
  if( i>=0 ) p->aCol[i].sortOrder = collType;
}

/*
** Come up with a new random value for the schema cookie.  Make sure
** the new value is different from the old.
**
** The schema cookie is used to determine when the schema for the
** database changes.  After each schema change, the cookie value
** changes.  When a process first reads the schema it records the
** cookie.  Thereafter, whenever it goes to access the database,
** it checks the cookie to make sure the schema has not changed
** since it was last read.
**
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqliteChangeCookie(sqlite *db, Vdbe *v){
  if( db->next_cookie==db->aDb[0].schema_cookie ){
    unsigned char r;
    sqliteRandomness(1, &r);
    db->next_cookie = db->aDb[0].schema_cookie + r + 1;
    db->flags |= SQLITE_InternChanges;
    sqliteVdbeAddOp(v, OP_Integer, db->next_cookie, 0);
    sqliteVdbeAddOp(v, OP_SetCookie, 0, 0);
  }
}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
*/
static int identLength(const char *z){
  int n;
  int needQuote = 0;
  for(n=0; *z; n++, z++){
    if( *z=='\'' ){ n++; needQuote=1; }
  }
  return n + needQuote*2;
}

/*
** Write an identifier onto the end of the given string.  Add
** quote characters as needed.
*/
static void identPut(char *z, int *pIdx, char *zIdent){
  int i, j, needQuote;
  i = *pIdx;
  for(j=0; zIdent[j]; j++){
    if( !isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
  }
  needQuote =  zIdent[j]!=0 || isdigit(zIdent[0])
                  || sqliteKeywordCode(zIdent, j)!=TK_ID;
  if( needQuote ) z[i++] = '\'';
  for(j=0; zIdent[j]; j++){
    z[i++] = zIdent[j];
    if( zIdent[j]=='\'' ) z[i++] = '\'';
  }
  if( needQuote ) z[i++] = '\'';
  z[i] = 0;
  *pIdx = i;
}

/*
** Generate a CREATE TABLE statement appropriate for the given
** table.  Memory to hold the text of the statement is obtained
** from sqliteMalloc() and must be freed by the calling function.
*/
static char *createTableStmt(Table *p){
  int i, k, n;
  char *zStmt;
  char *zSep, *zSep2, *zEnd;
  n = 0;
  for(i=0; i<p->nCol; i++){
    n += identLength(p->aCol[i].zName);
  }
  n += identLength(p->zName);
  if( n<40 ){
    zSep = "";
    zSep2 = ",";
    zEnd = ")";
  }else{
    zSep = "\n  ";
    zSep2 = ",\n  ";
    zEnd = "\n)";
  }
  n += 35 + 6*p->nCol;