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Added simple support for count(*) to SQL parser to quickly get number of rows in table

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This commit is contained in:
leecher1337 2015-08-20 14:35:09 +02:00
parent 0e508c82d8
commit 16bf355d6b
4 changed files with 36 additions and 4 deletions
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2
include/mdbsql.h
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@ -31,6 +31,7 @@
typedef struct { typedef struct {
MdbHandle *mdb; MdbHandle *mdb;
int all_columns; int all_columns;
int sel_count;
unsigned int num_columns; unsigned int num_columns;
GPtrArray *columns; GPtrArray *columns;
unsigned int num_tables; unsigned int num_tables;
@ -79,6 +80,7 @@ extern MdbSQLSarg *mdb_sql_alloc_sarg();
extern MdbHandle *mdb_sql_open(MdbSQL *sql, char *db_name); extern MdbHandle *mdb_sql_open(MdbSQL *sql, char *db_name);
extern int mdb_sql_add_sarg(MdbSQL *sql, char *col_name, int op, char *constant); extern int mdb_sql_add_sarg(MdbSQL *sql, char *col_name, int op, char *constant);
extern void mdb_sql_all_columns(MdbSQL *sql); extern void mdb_sql_all_columns(MdbSQL *sql);
extern void mdb_sql_sel_count(MdbSQL *sql);
extern int mdb_sql_add_column(MdbSQL *sql, char *column_name); extern int mdb_sql_add_column(MdbSQL *sql, char *column_name);
extern int mdb_sql_add_table(MdbSQL *sql, char *table_name); extern int mdb_sql_add_table(MdbSQL *sql, char *table_name);
extern void mdb_sql_dump(MdbSQL *sql); extern void mdb_sql_dump(MdbSQL *sql);

1
src/sql/lexer.l
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@ -45,6 +45,7 @@ null { return NUL; }
(<=) { return LTEQ; } (<=) { return LTEQ; }
(>=) { return GTEQ; } (>=) { return GTEQ; }
like { return LIKE; } like { return LIKE; }
count { return COUNT; }
[ \t\r] ; [ \t\r] ;
\"[^"]*\"\" { \"[^"]*\"\" {

29
src/sql/mdbsql.c
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@ -316,7 +316,7 @@ mdb_sql_dump_node(MdbSargNode *node, int level)
printf(" < %d\n", node->value.i); printf(" < %d\n", node->value.i);
break; break;
case MDB_GT: case MDB_GT:
printf(" < %d\n", node->value.i); printf(" > %d\n", node->value.i);
break; break;
case MDB_LIKE: case MDB_LIKE:
printf(" like %s\n", node->value.s); printf(" like %s\n", node->value.s);
@ -419,6 +419,12 @@ mdb_sql_all_columns(MdbSQL *sql)
{ {
sql->all_columns=1; sql->all_columns=1;
} }
void
mdb_sql_sel_count(MdbSQL *sql)
{
sql->sel_count=1;
}
int mdb_sql_add_column(MdbSQL *sql, char *column_name) int mdb_sql_add_column(MdbSQL *sql, char *column_name)
{ {
MdbSQLColumn *c; MdbSQLColumn *c;
@ -508,6 +514,7 @@ void mdb_sql_reset(MdbSQL *sql)
sql->sarg_stack = NULL; sql->sarg_stack = NULL;
sql->all_columns = 0; sql->all_columns = 0;
sql->sel_count = 0;
sql->max_rows = -1; sql->max_rows = -1;
} }
static void print_break(int sz, int first) static void print_break(int sz, int first)
@ -690,6 +697,26 @@ int found = 0;
return; return;
} }
mdb_read_columns(table); mdb_read_columns(table);
if (sql->sel_count && !sql->sarg_tree) {
MdbTableDef *ttable = mdb_create_temp_table(mdb, "#count");
char tmpstr[32];
gchar row_cnt[32];
unsigned char row_buffer[MDB_PGSIZE];
MdbField fields[1];
int row_size, tmpsiz;
mdb_sql_add_temp_col(sql, ttable, 0, "count", MDB_TEXT, 30, 0);
sprintf(tmpstr,"%d",table->num_rows);
tmpsiz = mdb_ascii2unicode(mdb, tmpstr, 0, row_cnt, 32);
mdb_fill_temp_field(&fields[0],row_cnt, tmpsiz, 0,0,0,0);
row_size = mdb_pack_row(ttable, row_buffer, 1, fields);
mdb_add_row_to_pg(ttable,row_buffer, row_size);
ttable->num_rows++;
sql->cur_table = ttable;
return;
}
mdb_read_indices(table); mdb_read_indices(table);
mdb_rewind_table(table); mdb_rewind_table(table);

8
src/sql/parser.y
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@ -41,8 +41,8 @@ static MdbSQL *g_sql;
%token <name> IDENT NAME PATH STRING NUMBER %token <name> IDENT NAME PATH STRING NUMBER
%token SELECT FROM WHERE CONNECT DISCONNECT TO LIST TABLES AND OR NOT %token SELECT FROM WHERE CONNECT DISCONNECT TO LIST TABLES AND OR NOT COUNT
%token DESCRIBE TABLE %token DESCRIBE TABLE
%token LTEQ GTEQ LIKE IS NUL %token LTEQ GTEQ LIKE IS NUL
@ -146,11 +146,13 @@ table:
; ;
column_list: column_list:
'*' { mdb_sql_all_columns(_mdb_sql(NULL)); } COUNT '(' '*' ')' { mdb_sql_sel_count(_mdb_sql(NULL)); }
| '*' { mdb_sql_all_columns(_mdb_sql(NULL)); }
| column | column
| column ',' column_list | column ',' column_list
; ;
column: column:
identifier { mdb_sql_add_column(_mdb_sql(NULL), $1); free($1); } identifier { mdb_sql_add_column(_mdb_sql(NULL), $1); free($1); }
; ;