mdbsql.c

直接存取Access97数据库文件(MDB)的工具库源码

#include "mdbsql.h"
#include <stdarg.h>

mdb_sql_error(char *fmt, ...)
{
va_list ap;

	va_start(ap, fmt);
	vfprintf (stderr,fmt, ap);
	va_end(ap);
	fprintf(stderr,"\n");
}
MdbSQL *mdb_sql_init()
{
MdbSQL *sql;

	mdb_init();
	sql = (MdbSQL *) g_malloc0(sizeof(MdbSQL));
	sql->columns = g_ptr_array_new();
	sql->tables = g_ptr_array_new();
	sql->sargs = g_ptr_array_new();

	return sql;
}

MdbSQLSarg *mdb_sql_alloc_sarg()
{
MdbSQLSarg *sql_sarg;
	sql_sarg = (MdbSQLSarg *) malloc(sizeof(MdbSQLSarg));
	memset(sql_sarg,0,sizeof(MdbSQLSarg));
	sql_sarg->sarg = (MdbSarg *) malloc(sizeof(MdbSarg));
	memset(sql_sarg->sarg,0,sizeof(MdbSarg));
	return sql_sarg;
}
MdbSQLColumn *mdb_sql_alloc_column()
{
MdbSQLColumn *c;

	c = (MdbSQLColumn *) malloc(sizeof(MdbSQLColumn));
	memset(c,0,sizeof(MdbSQLColumn));
	return c;
}
MdbSQLTable *mdb_sql_alloc_table()
{
MdbSQLTable *t;

	t = (MdbSQLTable *) malloc(sizeof(MdbSQLTable));
	memset(t,0,sizeof(MdbSQLTable));
	return t;
}

MdbHandle *mdb_sql_open(MdbSQL *sql, char *db_name)
{
int fail = 0;
	if (!(sql->mdb = mdb_open(db_name))) {
		if (!strstr(db_name, ".mdb")) {
			char *tmpstr = (char *) malloc(strlen(db_name)+5);
			strcpy(tmpstr,db_name);
			strcat(tmpstr,".mdb");
			if (!(sql->mdb = mdb_open(tmpstr))) {
				fail++;
			}
			free(tmpstr);
		} else {
			fail++;
		}
	}
	if (fail) {
		mdb_sql_error("Unable to locate database %s", db_name);
	}
	return sql->mdb;
	
}
int mdb_sql_add_sarg(MdbSQL *sql, char *col_name, int op, char *constant)
{
MdbSQLSarg *sql_sarg;

	sql_sarg = mdb_sql_alloc_sarg();
	sql_sarg->col_name = g_strdup(col_name);
	sql_sarg->sarg->op = op;
	sql_sarg->sarg->value.i = atoi(constant);
	g_ptr_array_add(sql->sargs, sql_sarg);
	sql->num_sargs++;
}
int mdb_sql_all_columns(MdbSQL *sql)
{
	sql->all_columns=1;	
}
int mdb_sql_add_column(MdbSQL *sql, char *column_name)
{
MdbSQLColumn *c, *cp;

	c = mdb_sql_alloc_column();
	c->name = g_strdup(column_name);
	g_ptr_array_add(sql->columns, c);
	sql->num_columns++;
	return 0;
}
int mdb_sql_add_table(MdbSQL *sql, char *table_name)
{
MdbSQLTable *t;

	t = mdb_sql_alloc_table();
	t->name = g_strdup(table_name);
	t->alias = NULL;
	g_ptr_array_add(sql->tables, t);
	sql->num_tables++;
	return 0;
}
void mdb_sql_dump(MdbSQL *sql)
{
int i;
MdbSQLColumn *c;
MdbSQLTable *t;

	for (i=0;i<sql->num_columns;i++) {
		c = g_ptr_array_index(sql->columns,i);
		printf("column = %s\n",c->name);
	}
	for (i=0;i<sql->num_tables;i++) {
		t = g_ptr_array_index(sql->tables,i);
		printf("table = %s\n",t->name);
	}
}
void mdb_sql_exit(MdbSQL *sql)
{
int i;
MdbSQLColumn *c;
MdbSQLTable *t;
MdbSQLSarg *sql_sarg;

	for (i=0;i<sql->num_columns;i++) {
		c = g_ptr_array_index(sql->columns,i);
		if (c->name) g_free(c->name);
	}
	for (i=0;i<sql->num_tables;i++) {
		t = g_ptr_array_index(sql->tables,i);
		if (t->name) g_free(t->name);
	}
	for (i=0;i<sql->num_sargs;i++) {
		sql_sarg = g_ptr_array_index(sql->sargs,i);
		if (sql_sarg->col_name) g_free(sql_sarg->col_name);
		if (sql_sarg->sarg) g_free(sql_sarg->sarg);
	}
	g_ptr_array_free(sql->columns,TRUE);
	g_ptr_array_free(sql->tables,TRUE);
	g_ptr_array_free(sql->sargs,TRUE);
}
void mdb_sql_reset(MdbSQL *sql)
{
int i;
MdbSQLColumn *c;
MdbSQLTable *t;
MdbSQLSarg *sql_sarg;

	for (i=0;i<sql->num_columns;i++) {
		c = g_ptr_array_index(sql->columns,i);
		if (c->name) g_free(c->name);
	}
	for (i=0;i<sql->num_tables;i++) {
		t = g_ptr_array_index(sql->tables,i);
		if (t->name) g_free(t->name);
	}
	for (i=0;i<sql->num_sargs;i++) {
		sql_sarg = g_ptr_array_index(sql->sargs,i);
		if (sql_sarg->col_name) g_free(sql_sarg->col_name);
		if (sql_sarg->sarg) g_free(sql_sarg->sarg);
	}
	g_ptr_array_free(sql->columns,TRUE);
	g_ptr_array_free(sql->tables,TRUE);
	g_ptr_array_free(sql->sargs,TRUE);

	sql->all_columns = 0;
	sql->num_columns = 0;
	sql->columns = g_ptr_array_new();
	sql->num_tables = 0;
	sql->tables = g_ptr_array_new();
	sql->num_sargs = 0;
	sql->sargs = g_ptr_array_new();
}
static void print_break(int sz, int first)
{
int i;
	if (first) {
		fprintf(stdout,"+");
	}
	for (i=0;i<sz;i++) {
		fprintf(stdout,"-");
	}
	fprintf(stdout,"+");
}
static void print_value(char *v, int sz, int first)
{
int i;
int vlen;

	if (first) {
		fprintf(stdout,"|");
	}
	vlen = strlen(v);
	for (i=0;i<sz;i++) {
		fprintf(stdout,"%c",i >= vlen ? ' ' : v[i]);
	}
	fprintf(stdout,"|");
}
void mdb_sql_listtables(MdbSQL *sql)
{
int i;
MdbCatalogEntry entry;
MdbHandle *mdb = sql->mdb;

	if (!mdb) {
		mdb_sql_error("You must connect to a database first");
		return;
	}
	mdb_read_catalog (mdb, MDB_TABLE);


	print_break (30,1);
	fprintf(stdout,"\n");
	print_value ("Tables",30,1);
	fprintf(stdout,"\n");
	print_break (30,1);
	fprintf(stdout,"\n");
 	/* loop over each entry in the catalog */
 	for (i=0; i < mdb->num_catalog; i++) {
     	entry = g_array_index (mdb->catalog, MdbCatalogEntry, i);
     	/* if it's a table */
     	if (entry.object_type == MDB_TABLE) {
       		if (strncmp (entry.object_name, "MSys", 4)) {
				print_value (entry.object_name,30,1);
				fprintf(stdout,"\n");
			}
		}
	}
	print_break (30,1);
	fprintf(stdout,"\n");
}
void mdb_sql_select(MdbSQL *sql)
{
int i,j;
MdbCatalogEntry entry;
MdbHandle *mdb = sql->mdb;
MdbTableDef *table = NULL;
MdbSQLTable *sql_tab;
char *bound_values[256]; 
MdbColumn *col;
MdbSQLColumn *sqlcol;
MdbSQLSarg *sql_sarg;
int found = 0;

	if (!mdb) {
		mdb_sql_error("You must connect to a database first");
		return;
	}

	sql_tab = g_ptr_array_index(sql->tables,0);

	mdb_read_catalog(mdb, MDB_TABLE);

	for (i=0;i<mdb->num_catalog;i++) {
		entry = g_array_index(mdb->catalog,MdbCatalogEntry,i);
		if (entry.object_type == MDB_TABLE &&
			!strcmp(entry.object_name,sql_tab->name)) {
				table = mdb_read_table(&entry);
				break;
		}
	}
	if (!table) {
		mdb_sql_error("%s is not a table in this database", sql_tab->name);
		/* the column and table names are no good now */
		mdb_sql_reset(sql);
		return;
	}
	mdb_read_columns(table);
	mdb_rewind_table(table);

	if (sql->all_columns) {
		for (i=0;i<table->num_cols;i++) {
			col=g_ptr_array_index(table->columns,i);
			sqlcol = mdb_sql_alloc_column();
			sqlcol->name = g_strdup(col->name);
			g_ptr_array_add(sql->columns, sqlcol);
			sql->num_columns++;
		}
	}
	for (i=0;i<sql->num_columns;i++) {
		sqlcol = g_ptr_array_index(sql->columns,i);
		found=0;
		for (j=0;j<table->num_cols;j++) {
			col=g_ptr_array_index(table->columns,j);
			if (!strcmp(sqlcol->name, col->name)) {
				bound_values[i] = (char *) malloc(MDB_BIND_SIZE);
				bound_values[i][0] = '\0';
				/* bind the column to its listed (SQL) position */
				mdb_bind_column(table, j+1, bound_values[i]);
				sqlcol->disp_size = mdb_col_disp_size(col);
				found=1;
				break;
			}
		}
		if (!found) {
			mdb_sql_error("Column %s not found",sqlcol->name);
			mdb_sql_reset(sql);
			return;
		}
	}

	/* now add back the sargs */
	for (i=0;i<sql->num_sargs;i++) {
		sql_sarg=g_ptr_array_index(sql->sargs,i);
		fprintf(stdout,"Sarg for %s\n",sql_sarg->col_name);
		mdb_add_sarg_by_name(table,sql_sarg->col_name, sql_sarg->sarg);
	}
	
	/* print header */
	for (j=0;j<sql->num_columns;j++) {
		sqlcol = g_ptr_array_index(sql->columns,j);
		print_break(sqlcol->disp_size, !j);
	}
	fprintf(stdout,"\n");
	for (j=0;j<sql->num_columns;j++) {
		sqlcol = g_ptr_array_index(sql->columns,j);
		print_value(sqlcol->name,sqlcol->disp_size,!j);
	}
	fprintf(stdout,"\n");
	for (j=0;j<sql->num_columns;j++) {
		sqlcol = g_ptr_array_index(sql->columns,j);
		print_break(sqlcol->disp_size, !j);
	}
	fprintf(stdout,"\n");

	/* print each row */
	while(mdb_fetch_row(table)) {
  		for (j=0;j<sql->num_columns;j++) {
			sqlcol = g_ptr_array_index(sql->columns,j);
			print_value(bound_values[j],sqlcol->disp_size,!j);
		}
		fprintf(stdout,"\n");
	}

	/* footer */
	for (j=0;j<sql->num_columns;j++) {
		sqlcol = g_ptr_array_index(sql->columns,j);
		print_break(sqlcol->disp_size, !j);
	}

	fprintf(stdout,"\n");
	/* clean up */
	for (j=0;j<sql->num_columns;j++) {
		if (bound_values[j]) free(bound_values[j]);
	}

	/* the column and table names are no good now */
	mdb_sql_reset(sql);
}