COM_STMT_EXECUTE
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COM_STMT_EXECUTE
Executes a previously prepared statement.
If a specific data is big, it can be send appart prior to this command (see COM_STMT_SEND_LONG_DATA).
Direction
client to server
Fields
- int<1> 0x17 : COM_STMT_EXECUTE header
- int<4> statement id
- int<1> flags:
- int<4> Iteration count
- if (param_count > 0)
- if (Iteration count == 1)
- byte<(param_count + 7)/8> null bitmap
- byte<1> new-params-bound-flag(0 / 1)
- if (new-params-bound-flag)
- for each parameter :
- byte<2> parameter types
- for each parameter :
- for each iteration (i.e interation_count times)
- for each parameter (i.e param_count times)
- if (indicator_variable_used &&
extended_capabilities & MARIADB_CLIENT_STMT_BULK_OPERATIONS >> 32)
- int<1> indicator_variable (0 = null value, 1 =default value)
- byte<n> binary parameter value
- if (indicator_variable_used &&
extended_capabilities & MARIADB_CLIENT_STMT_BULK_OPERATIONS >> 32)
- for each parameter (i.e param_count times)
- if (Iteration count == 1)
Flag
| 0 | no cursor |
| 1 | read only |
| 2 | cursor for update |
| 4 | scrollable cursor |
| 128 | return all insert ids |
Parameter type
- byte<1> : field type
- byte<1> : parameter type flag
parameter type flag byte:
| 64 | indicator variable used (if extended_capabilities & MARIADB_CLIENT_STMT_BULK_OPERATIONS >> 32) |
| 128 | unsigned |
NULL-Bitmap
The NULL-Bitmap indicate if parameters are null (one bit per parameter).
NULL-bitmap size is (parameter number + 7) / 8
COM_STMT_EXECUTE response
server can answer with 3 differents responses :
- 0xff : ERR_Packet if any error occur
- 0x00 :OK_packet when query execution works without resultset
- Or a Resultset, when query execution return rows (in case of SELECT query for example)
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